The impact of Secondary Antioxidant DLTP on the physical appearance and dimensional stability of molded articles

The Impact of Secondary Antioxidant DLTP on the Physical Appearance and Dimensional Stability of Molded Articles

Introduction: A Touch of Science in Everyday Plastics

When you pick up a plastic bottle, snap shut a toy box, or even admire the sleek dashboard of your car, you’re probably not thinking about antioxidants. But believe it or not, behind that glossy surface and rigid structure lies a carefully orchestrated chemical ballet—one where secondary antioxidants like DLTP (Dilauryl Thiodipropionate) play a starring role.

In the world of polymer processing, especially for molded articles, appearance and dimensional stability are more than just aesthetic concerns—they’re critical to performance, longevity, and customer satisfaction. That’s where DLTP steps in, quietly working behind the scenes to ensure that plastics don’t yellow, warp, crack, or otherwise fall apart under stress or heat.

This article dives deep into the impact of DLTP on molded products, exploring how this unassuming antioxidant influences both the looks and structural integrity of polymers. Along the way, we’ll sprinkle in some science, practical applications, and yes—even a few tables to make things clearer.

What Is DLTP? And Why Should You Care?

DLTP stands for Dilauryl Thiodipropionate, a type of secondary antioxidant commonly used in polymer formulations. Unlike primary antioxidants (like hindered phenols), which directly scavenge free radicals, secondary antioxidants act as hydroperoxide decomposers. They break down harmful hydroperoxides before they can trigger further degradation reactions.

Think of DLTP as the cleanup crew at a chemistry party—where primary antioxidants are the bouncers keeping troublemakers out, DLTP is mopping up spills and tidying up after the chaos has started.

Chemical Profile of DLTP

Property	Value
Molecular Formula	C₂₆H₅₀O₄S
Molecular Weight	458.7 g/mol
Appearance	White to slightly yellow solid
Melting Point	~35–40°C
Solubility in Water	Insoluble
Compatibility	Polyolefins, PVC, ABS, PS

DLTP is particularly effective in polyolefins such as polyethylene (PE) and polypropylene (PP), which are widely used in injection molding, blow molding, and extrusion processes.

Why Molded Articles Need Antioxidants

Molding involves heating polymers until they become pliable, then forcing them into a mold to cool and solidify. During this process, polymers are exposed to high temperatures, shear forces, and sometimes oxygen, all of which accelerate oxidative degradation.

Degradation isn’t just bad for the material—it shows up visually:

Yellowing or discoloration
Surface cracking or crazing
Loss of gloss or texture
Brittleness

From a functional standpoint, oxidation can also lead to:

Reduced tensile strength
Poor impact resistance
Dimensional instability (e.g., warping)

That’s where antioxidants like DLTP come in, helping to preserve both the look and feel of molded parts.

DLTP’s Role in Enhancing Physical Appearance

Let’s start with the obvious: aesthetics. No one wants a cracked, yellowed baby toy or a discolored dashboard. DLTP helps maintain the visual appeal of molded articles by inhibiting oxidative degradation during processing and long-term use.

1. Color Retention

One of the most noticeable effects of DLTP is its ability to prevent yellowing, especially in white or light-colored polymers.

A study by Zhang et al. (2019) showed that adding 0.1% DLTP to polypropylene significantly reduced yellowness index (YI) values after thermal aging at 120°C for 72 hours.

Sample	Yellowness Index (Initial)	Yellowness Index (After Aging)
PP without DLTP	2.1	10.6
PP with 0.1% DLTP	2.0	4.3
PP with 0.3% DLTP	2.0	3.1

As shown above, even small amounts of DLTP can have a dramatic effect on color retention.

2. Surface Quality

DLTP also contributes to surface smoothness and gloss. Without proper antioxidant protection, polymers may develop surface defects like orange peel, streaks, or dull patches.

In an industrial trial conducted by a major automotive supplier, parts molded with DLTP exhibited a 20% increase in gloss compared to control samples. This improvement was attributed to better flow and less degradation during processing.

3. Long-Term Clarity

For transparent materials like polystyrene (PS) or acrylics, clarity is king. DLTP helps prevent haze formation caused by oxidation-induced micro-cracking or phase separation.

A 2021 study published in Polymer Degradation and Stability found that DLTP-treated PS sheets retained over 95% transparency after 1000 hours of UV exposure, while untreated samples dropped below 80%.

DLTP and Dimensional Stability: Keeping Things in Shape

Dimensional stability refers to a material’s ability to maintain its shape and size under various conditions—especially temperature changes, humidity, and mechanical stress.

In molded articles, poor dimensional stability often manifests as:

Warpage (bending or twisting)
Shrinkage or swelling
Cracking at stress points

DLTP helps combat these issues by reducing internal stresses and preventing molecular chain scission or crosslinking caused by oxidation.

1. Reducing Warpage in Injection Molding

Warpage is a common defect in injection-molded parts, especially those with uneven wall thicknesses. It occurs due to non-uniform cooling and residual stresses.

Adding DLTP to the polymer formulation reduces oxidative degradation during the high-temperature phase of molding, which in turn minimizes stress buildup.

An experiment by Wang et al. (2020) measured the warpage of polypropylene gears with and without DLTP:

Sample	Warpage (% deviation from design)
PP without DLTP	1.8%
PP with 0.2% DLTP	0.9%
PP with 0.5% DLTP	0.6%

Even modest additions of DLTP led to a significant reduction in part distortion.

2. Controlling Shrinkage and Expansion

Polymers naturally shrink as they cool after molding. However, oxidative degradation can exacerbate this behavior, leading to unpredictable dimensional changes.

DLTP helps stabilize the polymer matrix, ensuring more consistent shrinkage rates. In a comparative test between treated and untreated HDPE samples, DLTP reduced post-molding shrinkage variation by nearly 30%.

Parameter	Untreated HDPE	Treated with 0.3% DLTP
Avg. Shrinkage (%)	2.1	1.5
Std Deviation	±0.3	±0.1

This consistency is crucial in industries like electronics and medical devices, where tight tolerances are non-negotiable.

3. Resistance to Environmental Stress Cracking

Environmental stress cracking (ESC) is a silent killer of plastic parts, especially when exposed to chemicals, moisture, or UV radiation. DLTP enhances resistance by preserving polymer chain integrity and reducing susceptibility to external agents.

In a simulated weathering test, DLTP-treated polyethylene pipes showed no signs of cracking after 1500 hours, whereas untreated samples began showing micro-cracks after just 800 hours.

Synergies with Other Additives: Teamwork Makes the Dream Work

DLTP doesn’t work alone. It plays well with others—especially primary antioxidants like Irganox 1010 or 1076. Together, they form a powerful defense system against oxidative damage.

Additive	Function	Synergy with DLTP
Irganox 1010	Radical scavenger	Complements DLTP by neutralizing free radicals after DLTP breaks down peroxides
UV Stabilizers (e.g., HALS)	Protects against UV degradation	Works alongside DLTP to prevent photo-oxidative breakdown
Lubricants	Improves flow	DLTP does not interfere with lubricity but enhances overall melt stability

A 2018 paper in Journal of Applied Polymer Science highlighted a case where combining 0.2% DLTP with 0.1% Irganox 1010 improved both color retention and flexural strength in polyethylene film by over 40% compared to using either additive alone.

Processing Considerations: How Much DLTP Do You Really Need?

DLTP is typically added in concentrations ranging from 0.05% to 1.0%, depending on the application and severity of processing conditions.

Here’s a general guideline:

Application	Recommended DLTP Level
General-purpose packaging	0.05–0.1%
Automotive components	0.1–0.3%
Electrical insulation	0.2–0.5%
Industrial piping	0.3–1.0%

Too little DLTP may leave the polymer vulnerable; too much can lead to blooming (migration to the surface) or unnecessary cost.

Also, DLTP should be added early in the compounding stage to ensure even dispersion. Its low melting point allows it to mix well with molten polymer, making it compatible with standard twin-screw extruders and injection molding machines.

Real-World Applications: From Toys to Turbines

DLTP finds use across a wide range of industries. Here are just a few examples:

1. Consumer Goods – Keeping Kids Happy

Toys, food containers, and household items often use polypropylene or polyethylene. DLTP ensures these products remain colorful, safe, and durable—even when left in the sun or dropped repeatedly.

2. Automotive – Under the Hood and Beyond

Engine components, dashboards, and bumpers require materials that can withstand heat, vibration, and UV exposure. DLTP helps automotive plastics stay strong and dimensionally stable for years.

3. Medical Devices – Precision Matters

Medical tubing, syringes, and diagnostic equipment demand materials that won’t degrade over time. DLTP helps maintain sterility and functionality, especially when sterilization involves heat or gamma radiation.

4. Industrial Equipment – Tough as Nails

Piping systems, conveyor belts, and machine housings need materials that resist wear and environmental stress. DLTP boosts longevity in harsh environments.

Conclusion: DLTP – The Unsung Hero of Plastic Perfection

In the grand theater of polymer science, DLTP might not grab headlines like graphene or carbon nanotubes, but its contribution to molded articles is no less significant. By protecting against oxidative degradation, DLTP preserves the physical appearance and dimensional stability of plastics—ensuring that what comes out of the mold stays beautiful, strong, and true to form.

So next time you admire a shiny new product or rely on a sturdy plastic component, tip your hat to DLTP—the quiet guardian of polymer perfection 🛡️✨.

References

Zhang, L., Li, H., & Chen, J. (2019). Effect of secondary antioxidants on color stability of polypropylene. Polymer Testing, 75, 123–130.
Wang, Y., Zhao, R., & Liu, X. (2020). Influence of DLTP on warpage in injection-molded polypropylene gears. Journal of Materials Processing Technology, 280, 116632.
Kim, S., Park, T., & Lee, K. (2021). UV resistance of polystyrene films with combined antioxidant systems. Polymer Degradation and Stability, 185, 109501.
Gupta, A., Sharma, P., & Singh, R. (2018). Synergistic effects of primary and secondary antioxidants in polyethylene. Journal of Applied Polymer Science, 135(15), 46021.
European Plastics Converters Association. (2022). Best Practices in Antioxidant Use for Thermoplastic Processing. Brussels: EUPC Publications.

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Secondary Antioxidant DLTP for food contact applications, meeting stringent safety and purity standards

DLTP: The Unsung Hero of Food Safety – A Secondary Antioxidant for Food Contact Applications

When it comes to food preservation and safety, antioxidants are the unsung heroes working behind the scenes. While primary antioxidants like BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole) often steal the spotlight, secondary antioxidants play a crucial supporting role—ensuring that our favorite snacks stay fresh, safe, and delicious.

One such secondary antioxidant is DLTP, or more formally, Dilauryl Thiodipropionate. Though not as well-known as its primary cousins, DLTP has carved out a niche in the world of food contact materials, where safety and purity are non-negotiable. In this article, we’ll dive deep into what makes DLTP tick, why it’s so valuable in food packaging applications, and how it meets—and exceeds—the stringent standards required for food safety.

What Exactly Is DLTP?

Let’s start with the basics. DLTP stands for Dilauryl Thiodipropionate, a chemical compound commonly used as a secondary antioxidant in polymer-based food contact materials. Its main job? To stabilize plastics against oxidative degradation caused by heat, light, and oxygen exposure during processing and long-term storage.

But wait—what’s a secondary antioxidant, you ask?

Unlike primary antioxidants that directly scavenge free radicals, secondary antioxidants work more like bodyguards—they prevent the formation of free radicals by neutralizing peroxides. Think of them as the cleanup crew that steps in before things get messy.

DLTP is particularly effective in polyolefins like polyethylene (PE) and polypropylene (PP), which are widely used in food packaging due to their flexibility, clarity, and cost-effectiveness.

Why Use DLTP in Food Contact Applications?

The answer lies in three words: safety, purity, and performance.

In food packaging, any additive must meet rigorous regulatory standards to ensure it doesn’t leach harmful substances into the food. DLTP checks all these boxes:

It’s non-toxic at recommended usage levels.
It has low volatility, meaning it won’t evaporate easily during high-temperature processing.
It offers excellent thermal stability, making it ideal for use in extrusion and molding processes.
It enhances the shelf life of both the packaging material and the food inside.

Moreover, DLTP works synergistically with primary antioxidants, boosting overall stabilization performance without compromising safety.

Regulatory Compliance and Global Standards

When it comes to food contact materials, regulatory compliance isn’t just a checkbox—it’s a lifeline. DLTP has been extensively studied and approved by several global regulatory bodies:

Regulatory Body	Standard/Regulation	Relevant Clause
FDA (USA)	21 CFR §178.2010	Allowed as an antioxidant in polymers
EFSA (EU)	Regulation (EU) No 10/2011	Permits use in plastic food contact materials
China	GB 9685-2016	Listed for use in food contact materials
Japan	JFSL Notification No. 370	Approved for use in food packaging resins

These approvals reflect years of testing and real-world application, ensuring that DLTP can be safely used across different regions and product types.

Performance Parameters of DLTP

To truly appreciate DLTP, let’s take a look at some key technical parameters:

Parameter	Value
Chemical Name	Dilauryl Thiodipropionate
Molecular Formula	C₂₈H₅₄O₄S
Molecular Weight	494.78 g/mol
Appearance	White to off-white powder or granules
Melting Point	~70°C
Density	~1.02 g/cm³
Solubility in Water	Insoluble
Solubility in Organic Solvents	Slightly soluble in acetone, ethanol
Flash Point	>200°C (closed cup)
Recommended Usage Level	0.05–0.3% by weight
Shelf Life	2 years (stored properly)
Compatibility	Good with polyolefins, polystyrene, ABS, etc.

As you can see from the table above, DLTP strikes a perfect balance between functionality and practicality. Its melting point allows it to blend well with molten polymers during processing, while its low solubility in water ensures it stays put once incorporated.

Real-World Applications of DLTP

DLTP shines brightest in food packaging films, containers, and caps made from polyethylene and polypropylene. Here are a few common applications:

1. Flexible Packaging Films

Used in snack bags, frozen food wraps, and vacuum-sealed pouches. DLTP helps maintain the film’s integrity even when exposed to heat sealing or cold storage.

2. Food Containers

From yogurt cups to microwaveable meal trays, DLTP protects the plastic from yellowing or becoming brittle over time.

3. Bottle Caps and Lids

Exposure to sunlight and temperature fluctuations can degrade plastic closures. DLTP acts as a shield, preserving the cap’s mechanical properties and seal integrity.

4. Medical Food Packaging

In specialized nutrition products and infant formulas, DLTP ensures that packaging remains inert and doesn’t interact with sensitive contents.

Synergistic Effects with Other Additives

DLTP doesn’t work alone. When combined with primary antioxidants like Irganox 1010 or Irganox 1076, it forms a powerful antioxidant system. This synergy enhances protection against oxidative stress without increasing toxicity risk.

Here’s a quick comparison of DLTP with other common antioxidants:

Additive Type	Primary/Secondary	Function	Volatility	Toxicity Risk
BHT	Primary	Radical scavenger	Medium	Low
Irganox 1010	Primary	High molecular weight stabilizer	Low	Very low
DLTP	Secondary	Peroxide decomposer	Low	Very low
Phosphite esters	Secondary	Peroxide neutralizer	Medium	Low

This table shows that DLTP complements other additives well, especially in systems where long-term thermal stability is needed.

Case Studies and Research Insights

Several studies have highlighted the effectiveness of DLTP in food packaging applications. For instance:

Zhang et al. (2019) studied the migration behavior of various antioxidants in polypropylene baby bottles. They found that DLTP showed significantly lower migration rates compared to other secondary antioxidants, making it safer for infant use 🍼.
Kumar & Singh (2021) evaluated the impact of DLTP on the shelf life of HDPE milk jugs. Their results indicated that adding 0.2% DLTP extended the container’s useful life by up to 30%, reducing brittleness and discoloration.
European Plastics Converters Association (EuPC, 2020) conducted a lifecycle analysis of food-grade polymers with and without DLTP. The study concluded that incorporating DLTP reduced plastic waste by improving durability and recyclability.

These findings underscore DLTP’s importance not only in maintaining product safety but also in contributing to sustainability goals within the packaging industry.

Challenges and Considerations

While DLTP is generally safe and effective, there are a few considerations to keep in mind:

Dosage Optimization: Too little may not provide sufficient protection; too much could affect transparency or increase costs unnecessarily.
Processing Conditions: DLTP performs best under moderate shear and temperature conditions. Excessive heat can cause premature decomposition.
Regulatory Updates: Regulations around food contact materials evolve. Manufacturers must stay informed about regional changes in allowable concentrations or labeling requirements.

Future Outlook and Innovations

With growing consumer demand for longer shelf life, sustainable packaging, and minimal chemical exposure, the future looks bright for DLTP and similar additives.

Emerging trends include:

Bio-based DLTP analogs: Researchers are exploring plant-derived alternatives that mimic DLTP’s performance while being more environmentally friendly.
Nanocomposites: Combining DLTP with nanomaterials like clay or graphene could enhance barrier properties and antioxidant efficiency.
Smart Packaging Integration: Future food packaging might incorporate DLTP alongside sensors that monitor freshness and alert consumers to spoilage.

Conclusion

DLTP may not be the first name that comes to mind when we think about food safety, but it plays a critical role in protecting both packaging and the food inside. With its excellent thermal stability, low toxicity, and strong regulatory backing, DLTP stands out as a reliable secondary antioxidant for food contact applications.

So next time you grab a bag of chips, a yogurt cup, or a bottle of juice, remember that somewhere inside that shiny plastic shell is a quiet guardian named DLTP, working hard to keep your food safe and your experience enjoyable. 🛡️🍎🍫

References

Zhang, Y., Li, M., & Wang, H. (2019). Migration of antioxidants from polypropylene baby bottles: A comparative study. Food Additives & Contaminants, 36(5), 712–721.
Kumar, R., & Singh, P. (2021). Effect of secondary antioxidants on the aging resistance of HDPE milk containers. Journal of Applied Polymer Science, 138(15), 50234.
European Plastics Converters Association (EuPC). (2020). Lifecycle Assessment of Food Contact Polymers. Brussels: EuPC Publications.
U.S. Food and Drug Administration (FDA). (2022). Code of Federal Regulations Title 21, Section 178.2010.
National Health Commission of the People’s Republic of China. (2016). GB 9685-2016 – National Food Safety Standard for Use of Additives in Food Contact Materials and Articles.
Ministry of Health, Labour and Welfare of Japan. (2018). Notification No. 370 of the Ministry of Health, Labour and Welfare regarding Food Sanitation Law.
European Food Safety Authority (EFSA). (2011). Commission Regulation (EU) No 10/2011 on Plastic Materials and Articles Intended to Come into Contact with Food.
ISO/TC 55/SC 10. (2020). Plastics – Determination of antioxidant content in polyolefins using HPLC.
Smith, J., & Patel, A. (2020). Advances in secondary antioxidants for food packaging: A review. Trends in Food Science & Technology, 98, 112–123.
Chen, X., Liu, W., & Zhao, Q. (2022). Green alternatives to synthetic antioxidants in food contact polymers. Green Chemistry Letters and Reviews, 15(3), 201–210.

If you enjoyed this article and want to know more about food packaging innovations or polymer chemistry, feel free to drop a comment below! 👇 Let’s keep the conversation rolling!

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Enhancing the mechanical properties and processability of recycled polymers using Secondary Antioxidant DLTP

Enhancing the Mechanical Properties and Processability of Recycled Polymers Using Secondary Antioxidant DLTP

Introduction: A Second Life for Plastics

Imagine a world where every plastic bottle you throw away gets a second chance—no, not just to be buried in landfills or float in oceans, but to live on as something useful again. That’s the dream of recycling. But like any aging hero, recycled polymers often struggle with wear and tear. Their mechanical strength dwindles, their colors fade, and processing them becomes a headache.

Enter DLTP, short for Dilauryl Thiodipropionate—a secondary antioxidant that might just be the fountain of youth for recycled plastics. In this article, we’ll explore how DLTP works its magic, why it’s becoming a favorite among polymer engineers, and what the future holds for sustainable materials science.

So grab your lab coat (or at least a coffee mug), and let’s dive into the fascinating world of polymer rejuvenation!

What is DLTP?

DLTP stands for Dilauryl Thiodipropionate, a type of secondary antioxidant commonly used in polymer stabilization. Unlike primary antioxidants that directly scavenge free radicals, DLTP belongs to the thioester family, which works by deactivating hydroperoxides formed during thermal or oxidative degradation.

In simpler terms: think of DLTP as a cleanup crew that mops up dangerous chemicals before they can cause more damage. It doesn’t stop the fire, but it prevents it from spreading.

Chemical Structure and Properties

Property	Value
Molecular Formula	C₂₆H₅₀O₄S
Molecular Weight	458.73 g/mol
Appearance	White to off-white waxy solid
Melting Point	~60–65°C
Solubility in Water	Practically insoluble
Compatibility	Polyolefins, PVC, ABS, PS

DLTP is particularly popular in polyolefins like polyethylene (PE) and polypropylene (PP), which are widely used in packaging, automotive parts, and textiles—many of which are prime candidates for recycling.

The Problem with Recycled Polymers

Recycling is great in theory, but in practice, it’s far from perfect. Each time a polymer is melted down and reprocessed, it undergoes thermal and oxidative degradation. This leads to:

Chain scission (breaking of polymer chains)
Crosslinking (uncontrolled bonding between chains)
Discoloration
Loss of impact strength
Poor processability

These changes make recycled materials less desirable than virgin resins. For example, recycled polypropylene may lose up to 30% of its tensile strength after just one cycle if not properly stabilized.

Here’s a quick comparison of mechanical properties between virgin and once-recycled PP:

Property	Virgin PP	Recycled PP
Tensile Strength (MPa)	30–35	21–25
Elongation at Break (%)	200–400	100–200
Impact Strength (kJ/m²)	3–5	1–2

Clearly, something needs to be done to restore the glory of these tired polymers—and that’s where DLTP comes in.

How DLTP Works: The Science Behind the Magic

DLTP operates differently from hindered phenolic antioxidants (primary antioxidants). Instead of scavenging free radicals directly, DLTP functions through a hydroperoxide decomposition mechanism.

When polymers degrade under heat or UV exposure, they form hydroperoxides (ROOH), which are unstable and prone to further reactions. These reactions generate more radicals, leading to a vicious cycle of degradation.

DLTP interrupts this cycle by reacting with ROOH to form stable sulfides and alcohols:

2 ROOH + DLTP → (RO)₂S + HOOCCH₂CH₂COOH + H₂O

This reaction effectively halts further oxidative damage. And because DLTP itself isn’t consumed in the process, it remains active for multiple cycles—making it ideal for long-term protection and recycling applications.

Benefits of DLTP in Recycled Polymer Systems

1. Improved Thermal Stability

Thermal degradation is a major concern during reprocessing. Studies have shown that adding 0.1–0.3% DLTP significantly increases the thermal decomposition temperature (Td) of recycled polyolefins.

For instance, a study by Zhang et al. (2021) found that adding 0.2% DLTP increased the Td of recycled HDPE from 392°C to 410°C, reducing chain scission and maintaining molecular weight.

2. Retention of Mechanical Properties

As mentioned earlier, recycled polymers suffer from reduced strength and toughness. DLTP helps preserve these properties by preventing oxidative crosslinking and chain breakage.

In a comparative test conducted by Kumar et al. (2020), recycled LDPE samples with and without DLTP were subjected to tensile testing:

Sample	Tensile Strength (MPa)	Elongation at Break (%)
Without DLTP	9.4	180
With 0.2% DLTP	11.8	250

That’s a 25% improvement in strength and a 39% increase in ductility—not bad for a small additive!

3. Enhanced Color Stability

Discoloration is a common issue in recycled polymers, especially those exposed to high temperatures or UV light. DLTP helps maintain the original color by inhibiting oxidation-induced chromophore formation.

A visual comparison of recycled PP pellets showed noticeable yellowing in untreated samples versus white-to-off-white appearance in DLTP-treated ones.

Sample	YI (Yellow Index)
Virgin PP	3.2
Recycled PP (No Additive)	8.7
Recycled PP + 0.15% DLTP	5.1

The Yellow Index (YI) dropped significantly with DLTP treatment, making the material more acceptable for consumer-facing products.

4. Better Processability

During extrusion or injection molding, degraded polymers tend to become sticky, brittle, or uneven. DLTP improves melt flow and reduces viscosity fluctuations.

A melt flow index (MFI) test on recycled PP showed:

Sample	MFI (g/10 min)
Virgin PP	12.5
Recycled PP	8.2
Recycled PP + 0.2% DLTP	11.0

The MFI improved by 34%, meaning smoother processing and fewer defects.

Comparative Performance with Other Stabilizers

DLTP is often used in combination with primary antioxidants like Irganox 1010 or 1076. However, even when used alone, it outperforms some other secondary stabilizers.

Additive	Function	Effectiveness in Recycled PP
DLTP	Hydroperoxide decomposer	High
DSTDP	Similar to DLTP	Moderate
Irganox 1010	Radical scavenger	Medium
Irgafos 168	Phosphite-based	Good, but may hydrolyze easily

DLTP offers a good balance of stability, cost, and performance. Plus, unlike phosphites, it doesn’t produce volatile byproducts, making it safer for indoor applications.

Recommended Dosage and Processing Conditions

While DLTP is effective, too much of a good thing can backfire. Here’s a general guideline for using DLTP in recycled polymer systems:

Polymer Type	Recommended DLTP Loading	Notes
Polyethylene (LDPE, HDPE)	0.1–0.3%	Higher loading for thicker sections
Polypropylene (PP)	0.1–0.2%	Can be combined with phenolic antioxidants
ABS	0.1–0.25%	Helps prevent yellowing
PVC	0.05–0.15%	Use in combination with metal deactivators

DLTP should be added during the compounding stage, preferably via twin-screw extrusion. It disperses well due to its low melting point (~60°C) and compatibility with most thermoplastics.

Processing temperatures typically range from 180–240°C, depending on the base resin. At these temps, DLTP remains stable and reactive, offering real-time protection.

Case Studies: Real-World Applications

Case Study 1: Recycling Automotive Bumpers

An automotive recycling plant in Germany tested DLTP in reprocessing polypropylene bumpers. After three cycles, the bumpers retained 85% of their initial impact strength with only 0.2% DLTP, compared to 60% without any stabilizer.

"DLTP gave our recycled materials the durability needed for safety-critical components," said one engineer. "It’s like giving old plastic a gym membership."

Case Study 2: Packaging Film Reuse

A food packaging company in China used DLTP to stabilize recycled LDPE film. The treated film showed better clarity, less brittleness, and passed FDA migration tests.

They reported a 20% reduction in waste and extended the usable life of the material by two additional cycles.

Environmental and Safety Considerations

DLTP is generally considered safe and environmentally friendly. It has low toxicity, does not contain heavy metals, and complies with REACH and RoHS regulations.

However, like all additives, it should be handled with care. Dust inhalation during handling should be avoided, and proper ventilation is recommended.

From a sustainability standpoint, DLTP enables longer reuse cycles for polymers, thus reducing reliance on virgin plastic and cutting down carbon emissions.

Future Outlook and Research Directions

While DLTP has proven itself in many applications, researchers are always looking for ways to improve. Current trends include:

Hybrid antioxidant systems: Combining DLTP with UV absorbers or metal deactivators for broader protection.
Nanocomposites: Incorporating nanofillers like clay or graphene oxide with DLTP for enhanced barrier properties.
Bio-based antioxidants: Exploring natural alternatives to synthetic DLTP while maintaining performance.

One promising area is circular polymer systems, where DLTP could play a role in enabling infinite recycling loops. Imagine a world where no plastic ever truly dies—it just keeps getting better with age (and a little help from DLTP!).

Conclusion: DLTP – The Unsung Hero of Plastic Recycling

In the grand saga of polymer recycling, DLTP may not be the headline act, but it’s certainly the MVP. By preserving mechanical properties, improving processability, and extending the lifespan of recycled materials, DLTP is helping us move toward a greener, cleaner future—one pellet at a time.

So next time you toss a plastic bottle into the bin, remember: somewhere in a recycling plant, DLTP is working hard to give that bottle a new lease on life. And who knows? It might just come back as your next shampoo bottle, car part, or garden chair.

Let’s hear it for the unsung heroes of sustainability!

References

Zhang, L., Wang, J., & Li, H. (2021). Thermal Stabilization of Recycled HDPE Using Secondary Antioxidants. Polymer Degradation and Stability, 185, 109472.
Kumar, R., Singh, A., & Gupta, P. (2020). Effect of Antioxidants on Mechanical Properties of Recycled Low-Density Polyethylene. Journal of Applied Polymer Science, 137(22), 48655.
Chen, Y., Liu, X., & Zhao, M. (2019). Color and Rheological Stability of Recycled Polypropylene Stabilized with DLTP and Irganox 1010. Polymer Testing, 77, 105912.
European Chemicals Agency (ECHA). (2023). REACH Registration Dossier: Dilauryl Thiodipropionate.
ASTM International. (2022). Standard Test Methods for Tensile Properties of Plastics (ASTM D638).
ISO. (2020). Plastics – Determination of Melt Mass-Flow Rate (MFR) and Melt Volume-Flow Rate (MVR) (ISO 1133).
Wang, Q., Sun, Z., & Yang, F. (2018). Synergistic Effects of DLTP and UV Absorbers in Outdoor Polymeric Applications. Polymer Engineering & Science, 58(10), 1789–1797.
Kim, H. J., Park, S. W., & Lee, K. H. (2022). Long-Term Oxidative Stability of Recycled Polyolefins with Hybrid Antioxidant Systems. Macromolecular Materials and Engineering, 307(6), 2100632.
OECD Guidelines for the Testing of Chemicals. (2021). Test No. 201: Algal Growth Inhibition Test.
National Toxicology Program (NTP). (2019). Toxicity Evaluation of Dilauryl Thiodipropionate in Rodent Models.

💬 Got questions about DLTP or want to share your own experience with recycled polymers? Drop a comment below! Let’s keep the conversation rolling! 🚀

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Secondary Antioxidant DLTP ensures clarity and reduces yellowing in demanding film and fiber applications

Title: DLTP – The Unsung Hero of Polymer Clarity and Longevity

In the world of polymers, where clarity is king and yellowing is a villain that haunts every manufacturer’s dreams, there exists a quiet protector known as DLTP — short for Dilauryl Thiodipropionate. If you’re not familiar with this compound, don’t worry — it’s time to meet one of the most unassuming yet powerful players in the polymer industry.

Now, before your eyes glaze over at the mention of another chemical acronym, let me assure you — DLTP is more than just a mouthful of letters. It’s a secondary antioxidant that plays a starring role behind the scenes, ensuring that films stay clear, fibers remain bright, and manufacturers sleep soundly at night.

Let’s dive into what makes DLTP such a critical component in demanding film and fiber applications, how it works its magic, and why it deserves a standing ovation in the polymer hall of fame.

What Is DLTP and Why Should You Care?
The Science Behind Secondary Antioxidants
How DLTP Protects Polymers from Yellowing
Applications in Film and Fiber Industries
DLTP vs. Other Antioxidants: A Comparative Look
Key Technical Parameters of DLTP
Environmental and Safety Considerations
Case Studies and Real-World Performance
Future Trends and Innovations
Conclusion: DLTP – Small Molecule, Big Impact

1. What Is DLTP and Why Should You Care?

DLTP stands for Dilauryl Thiodipropionate, which is a type of secondary antioxidant used primarily in polymer formulations. Unlike primary antioxidants, which neutralize free radicals directly, secondary antioxidants like DLTP work by decomposing hydroperoxides — those pesky molecules that form during oxidation and can lead to chain scission, discoloration, and material degradation.

So why should you care about DLTP? Well, if you’ve ever looked through a plastic window that turned foggy or seen white fibers turn yellowish after exposure to heat or light, then you’ve witnessed firsthand what happens when antioxidants fail. DLTP steps in quietly and effectively to prevent these issues, especially in high-performance films and fibers where appearance and durability are paramount.

2. The Science Behind Secondary Antioxidants

Before we get too deep into DLTP, let’s take a moment to understand the broader class of chemicals it belongs to — secondary antioxidants.

Primary vs. Secondary Antioxidants

Feature	Primary Antioxidant	Secondary Antioxidant
Function	Scavenges free radicals	Decomposes hydroperoxides
Mechanism	Radical termination	Peroxide decomposition
Examples	Phenolic antioxidants (e.g., Irganox 1010)	Phosphites, thioesters (e.g., DLTP)
Stability	Generally lower thermal stability	Higher thermal stability

Secondary antioxidants act as a support system for primary antioxidants. They don’t stop the fire, but they help clean up the smoke afterward — preventing further damage and prolonging the life of the polymer.

DLTP, specifically, belongs to the thioester family of antioxidants. Its sulfur-containing structure gives it unique abilities to handle peroxides without compromising the clarity of the final product.

3. How DLTP Protects Polymers from Yellowing

Yellowing in polymers is often caused by oxidative degradation, particularly under heat or UV exposure. When polyolefins like polyethylene or polypropylene oxidize, they form carbonyl groups and conjugated systems that absorb visible light — giving the material that dreaded yellow tint.

Here’s where DLTP shines (literally):

Hydroperoxide Decomposition: DLTP reacts with hydroperoxides formed during oxidation, breaking them down into non-reactive species.
Metal Deactivation: It also helps deactivate metal ions that catalyze oxidation reactions.
Synergistic Effects: DLTP works well alongside phenolic antioxidants, enhancing overall protection without affecting transparency.

One study published in Polymer Degradation and Stability found that incorporating DLTP into polypropylene films significantly reduced yellowness index (YI) values after accelerated aging tests compared to samples without DLTP [1].

4. Applications in Film and Fiber Industries

DLTP finds its sweet spot in two major areas: films and fibers — both of which demand optical clarity and mechanical integrity.

In Film Applications

Whether it’s shrink wrap, food packaging, or agricultural films, clarity is crucial. Consumers want to see what they’re buying, and farmers need sunlight to pass through greenhouse covers. Any hint of yellowing or haze can render the product undesirable.

DLTP helps maintain:

Transparency
Gloss retention
Mechanical strength under stress

Application	Benefit of DLTP
Food Packaging Films	Prevents discoloration, maintains aesthetic appeal
Agricultural Films	Maintains light transmission, prolongs service life
Medical Films	Ensures sterility and visual clarity for safety-critical uses

In Fiber Applications

Synthetic fibers like polyester, polypropylene, and nylon are prone to degradation during spinning, weaving, and dyeing processes. High temperatures and prolonged processing times increase the risk of oxidation and yellowing.

DLTP comes to the rescue by:

Reducing color formation during melt processing
Enhancing long-term resistance to environmental stress
Improving spinnability and tensile strength

A 2018 Chinese study showed that adding 0.1–0.3% DLTP to polypropylene fibers significantly improved their whiteness index and reduced breakage during extrusion [2].

5. DLTP vs. Other Antioxidants: A Comparative Look

DLTP isn’t the only game in town. Let’s compare it with some other commonly used antioxidants:

Antioxidant	Type	Main Function	Thermal Stability	Compatibility with Polymers	Cost
DLTP	Secondary (Thioester)	Hydroperoxide decomposition	High	Excellent in polyolefins	Moderate
Irganox 1010	Primary (Phenolic)	Free radical scavenging	Moderate	Good	High
Irgafos 168	Secondary (Phosphite)	Peroxide decomposition	Very High	Good	High
DSTDP	Secondary (Thioester)	Similar to DLTP	High	Similar performance	Slightly higher cost
BHT	Primary ( Hindered Phenol )	Radical trapping	Low	Poor	Low

While DLTP may not be the flashiest antioxidant on the block, it offers a great balance between performance and cost. It doesn’t volatilize easily, it doesn’t migrate out of the polymer matrix, and it doesn’t interfere with the optical properties of the material — making it ideal for clear products.

6. Key Technical Parameters of DLTP

To better understand DLTP’s utility, here are some of its key technical specifications:

Parameter	Value
Chemical Name	Dilauryl Thiodipropionate
CAS Number	110-84-9
Molecular Formula	C₂₈H₅₄O₄S
Molecular Weight	~486.7 g/mol
Appearance	White to slightly yellow waxy solid
Melting Point	40–50°C
Solubility in Water	Insoluble
Solubility in Organic Solvents	Soluble in chlorinated solvents, esters, ketones
Density	~0.97 g/cm³
Flash Point	>200°C
Recommended Loading Level	0.05–0.5% by weight
Shelf Life	2 years (when stored properly)

DLTP is typically added during compounding or extrusion stages. Its low volatility ensures minimal loss during processing, and its compatibility with various resins allows for broad applicability.

7. Environmental and Safety Considerations

In today’s eco-conscious market, no additive can fly under the radar without addressing environmental impact and safety concerns.

According to the European Chemicals Agency (ECHA), DLTP is not classified as carcinogenic, mutagenic, or toxic to reproduction (CMR). It has low acute toxicity and is generally considered safe for industrial use [3].

However, as with all chemical additives, proper handling and disposal are essential. DLTP is not biodegradable, so waste containing DLTP should be disposed of in accordance with local regulations.

From a regulatory standpoint, DLTP complies with several international standards, including REACH and FDA guidelines for food contact materials — making it suitable for use in packaging and medical-grade polymers.

8. Case Studies and Real-World Performance

Let’s look at a few real-world examples of DLTP in action.

Case Study 1: Polypropylene Shrink Film Manufacturer

A leading manufacturer of polypropylene shrink films was facing complaints about yellowing after storage. After introducing 0.2% DLTP into their formulation, yellowness index dropped from 8.5 to 2.1 after 6 weeks of accelerated aging. Customer satisfaction soared, and returns plummeted 🎉.

Case Study 2: Synthetic Carpet Fiber Producer

A carpet fiber producer noticed increased breakage and discoloration during summer months. By blending DLTP with a phenolic antioxidant, they achieved a 30% improvement in fiber tensile strength and maintained consistent whiteness across batches.

Case Study 3: Agricultural Greenhouse Film

A greenhouse film supplier wanted to extend the outdoor lifespan of their product. Adding DLTP helped reduce photo-yellowing and improved UV resistance, allowing the film to last an additional 12 months in field trials conducted in southern China 🌞🌱.

These case studies highlight DLTP’s versatility and effectiveness in real-world scenarios.

9. Future Trends and Innovations

As polymer science continues to evolve, so does the demand for smarter, greener, and more efficient additives. While DLTP has stood the test of time, researchers are exploring ways to enhance its performance and sustainability.

Some current trends include:

Nanoencapsulation: Encapsulating DLTP in nanoparticles to improve dispersion and efficiency.
Bio-based Alternatives: Developing bio-derived thioesters that mimic DLTP’s performance while reducing reliance on petrochemicals.
Synergistic Blends: Combining DLTP with UV stabilizers and hindered amine light stabilizers (HALS) for multi-layered protection.
Digital Formulation Tools: Using AI-assisted modeling to optimize DLTP loading levels and predict performance outcomes.

A recent paper in Journal of Applied Polymer Science discussed the potential of using modified DLTP derivatives to enhance antioxidant efficiency in recycled polyolefins [4]. This opens exciting new avenues for DLTP’s future.

10. Conclusion: DLTP – Small Molecule, Big Impact

DLTP may not be the headline act in the polymer world, but it’s the unsung hero that keeps things looking fresh, running smoothly, and lasting longer. From protecting delicate food packaging to ensuring synthetic fibers retain their luster, DLTP plays a vital role in maintaining both aesthetics and functionality.

Its ability to combat yellowing, resist thermal breakdown, and work harmoniously with other additives makes it a go-to choice for formulators seeking clarity, longevity, and reliability.

So next time you admire a crystal-clear plastic bag or marvel at the resilience of synthetic fabric, tip your hat to DLTP — the silent guardian of polymer purity. 🧪✨

References

[1] Zhang, L., Wang, Y., & Liu, H. (2016). "Effect of secondary antioxidants on the thermal oxidation stability of polypropylene." Polymer Degradation and Stability, 129, 112–120.

[2] Chen, J., Li, M., & Zhou, F. (2018). "Antioxidant performance of DLTP in polypropylene fiber production." Chinese Journal of Polymer Science, 36(4), 451–458.

[3] ECHA (European Chemicals Agency). (2023). "Substance Evaluation – Dilauryl Thiodipropionate (DLTP)." Retrieved from ECHA database records.

[4] Kim, T., Park, S., & Lee, K. (2021). "Development of sustainable antioxidant systems for recycled polyolefins." Journal of Applied Polymer Science, 138(15), 50213.

If you enjoyed this journey through the world of antioxidants and polymers, feel free to share it with fellow chemists, engineers, or anyone who appreciates the unseen heroes of modern materials. And remember — sometimes the best solutions come in small, waxy packages 📦🧪.

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The application of Secondary Antioxidant DLTP significantly extends the lifespan of plastic products

The Application of Secondary Antioxidant DLTP Significantly Extends the Lifespan of Plastic Products

Introduction: The Silent Guardian of Plastics

Imagine a world without plastic. It’s almost unthinkable—plastic is everywhere, from your toothbrush to the dashboard of your car. But here’s the catch: as versatile and convenient as plastic is, it has one major weakness—it ages. Over time, exposure to heat, light, oxygen, and other environmental factors causes plastics to degrade. This degradation leads to brittleness, discoloration, and ultimately, failure.

Enter DLTP, or more formally, Dilauryl Thiodipropionate, a secondary antioxidant that plays a crucial role in slowing down this aging process. Though not as well-known as some primary antioxidants like hindered phenols, DLTP deserves its own spotlight for being the unsung hero behind many durable plastic products we use daily.

In this article, we’ll explore what makes DLTP so effective, how it works hand-in-hand with primary antioxidants, and why it’s become a go-to additive in industries ranging from packaging to automotive manufacturing. Along the way, we’ll sprinkle in some technical details, comparisons with other antioxidants, and even a few real-world examples to show just how powerful this little compound can be.

Let’s dive in!

What Is DLTP?

DLTP stands for Dilauryl Thiodipropionate, which might sound complicated, but once you break it down, it’s not too bad. It belongs to a family of compounds known as thioesters, and its chemical structure includes a sulfur atom at the center, flanked by two lauryl groups (long-chain fatty acids). This unique structure gives DLTP its antioxidant properties.

As a secondary antioxidant, DLTP doesn’t directly scavenge free radicals like primary antioxidants do. Instead, it acts more like a cleanup crew—it neutralizes harmful peroxides formed during oxidation, preventing them from causing further damage.

Here’s a quick summary of DLTP’s basic characteristics:

Property	Value
Chemical Name	Dilauryl Thiodipropionate
Molecular Formula	C₂₈H₅₄O₄S
Molecular Weight	486.79 g/mol
Appearance	White to off-white powder or granules
Melting Point	~50–60°C
Solubility	Insoluble in water; soluble in organic solvents
Odor	Slight characteristic odor

Now that we’ve introduced our main character, let’s talk about why antioxidants are so important in the first place.

Why Do Plastics Need Antioxidants?

Plastics are made up of long chains of molecules called polymers. While these chains give plastics their strength and flexibility, they’re also vulnerable to attack by oxygen—a process known as oxidative degradation.

When oxygen interacts with polymer chains, it forms free radicals, which are highly reactive species that can cause chain scission (breaking of the polymer chain) or cross-linking (where chains stick together unnaturally). Both processes lead to physical changes in the plastic—cracking, yellowing, loss of flexibility—and eventually, structural failure.

This is where antioxidants come into play. Think of them as bodyguards for your plastic—they prevent oxidative degradation by either scavenging free radicals or neutralizing the precursors that form them.

There are two main types of antioxidants used in plastics:

Primary Antioxidants (Free Radical Scavengers)
These include hindered phenols and aromatic amines, which directly react with free radicals to stop the chain reaction of oxidation.
Secondary Antioxidants (Peroxide Decomposers)
These include phosphites, thioesters, and yes—you guessed it—DLTP. Their job is to decompose hydroperoxides before they can generate free radicals.

While both types are important, using them together creates a synergistic effect, meaning the whole is greater than the sum of its parts. And that’s exactly where DLTP shines.

How Does DLTP Work?

DLTP operates through a mechanism known as hydroperoxide decomposition. When oxygen attacks a polymer, it forms hydroperoxides (ROOH), which are unstable and prone to breaking down into free radicals. Left unchecked, these radicals wreak havoc on the polymer matrix.

DLTP steps in and reacts with ROOH to convert them into harmless alcohols and sulfides. This stops the formation of free radicals before they can start a chain reaction.

Here’s a simplified version of the reaction:

$$
ROOH + DLTP → ROH + oxidized DLTP derivative
$$

Because DLTP doesn’t get consumed in the same way primary antioxidants do, it tends to last longer in the material. That means better long-term protection against thermal and oxidative stress.

Moreover, DLTP is particularly effective under high-temperature conditions, making it ideal for applications involving extrusion, injection molding, and other processing techniques where plastics are exposed to elevated temperatures.

Advantages of Using DLTP in Plastics

So why choose DLTP over other secondary antioxidants? Let’s take a look at its key benefits:

1. Excellent Peroxide Decomposition Efficiency

DLTP is one of the most efficient thioester-based antioxidants available. Its sulfur content allows it to effectively neutralize hydroperoxides, especially in polyolefins like polyethylene and polypropylene.

2. Good Thermal Stability

Unlike some antioxidants that break down under high heat, DLTP remains stable up to around 200°C. This makes it suitable for use in thermoplastic processing.

3. Low Volatility

Volatility can be a big issue with some additives—they tend to evaporate during processing, reducing effectiveness. DLTP, however, has low volatility, ensuring consistent performance throughout the product lifecycle.

4. Compatibility with Other Additives

DLTP works well alongside primary antioxidants like Irganox 1010 or Irganox 1076. This compatibility allows manufacturers to create custom antioxidant blends tailored to specific applications.

5. Cost-Effective

Compared to some phosphite-based antioxidants, DLTP offers good performance at a lower cost, making it an attractive option for industrial applications.

Let’s compare DLTP with some common secondary antioxidants:

Additive	Type	Function	Volatility	Cost	Best Used In
DLTP	Thioester	Peroxide decomposer	Low	Moderate	Polyolefins, PVC, rubber
Irgafos 168	Phosphite	Hydrolytic stabilizer	Medium	High	Engineering plastics
DSTDP	Thioester	Similar to DLTP	Medium	Moderate	Rubber, PE films
Calcium Stearate	Metal deactivator	Neutralizes metal ions	Low	Low	PVC stabilization

Applications of DLTP in Industry

DLTP isn’t just a lab curiosity—it’s widely used across several industries. Here are some of the most common applications:

1. Polyolefins (PE, PP)

Polyethylene and polypropylene are among the most widely used plastics globally. They’re used in everything from food packaging to automotive components. However, they’re also prone to oxidation, especially when exposed to UV light or high temperatures.

DLTP helps protect these materials during both processing and end-use. For example, in polyethylene pipes used for water distribution, DLTP significantly improves long-term durability by preventing oxidative degradation.

A study published in Polymer Degradation and Stability (Zhang et al., 2018) found that adding 0.1% DLTP to HDPE increased its thermal stability by 15–20%, extending service life under hot water conditions.

2. PVC Stabilization

PVC (polyvinyl chloride) is another major user of DLTP. During processing, PVC can release hydrochloric acid, which accelerates degradation. DLTP, often used in combination with metal stabilizers like calcium-zinc compounds, helps neutralize acidic byproducts and prolongs shelf life.

3. Rubber Compounds

In rubber products such as tires and seals, DLTP enhances resistance to ozone cracking and thermal aging. According to research by Tanaka et al. (2016) in the Journal of Applied Polymer Science, DLTP outperformed other thioesters in maintaining tensile strength after prolonged heat aging.

4. Cable Insulation

Electrical cables, especially those used in harsh environments, rely on DLTP to maintain insulation integrity. Oxidation can lead to electrical breakdowns, so antioxidants like DLTP are essential for safety and reliability.

5. Food Packaging

Yes, even in food packaging! Many flexible packaging films use polyolefins treated with antioxidants to ensure they don’t break down or leach harmful substances. DLTP is FDA-approved for indirect food contact, making it safe for these applications.

DLTP vs. Primary Antioxidants: A Dynamic Duo

You might be wondering: if DLTP doesn’t directly fight free radicals, why not just use primary antioxidants?

Great question! The truth is, relying solely on primary antioxidants is like sending only forwards into a soccer match—you need defenders too.

Primary antioxidants like Irganox 1010 or Ethanox 330 are excellent at trapping free radicals early on, but they get consumed in the process. Once they’re gone, there’s nothing left to stop oxidation.

That’s where DLTP comes in. By removing the root cause—hydroperoxides—DLTP reduces the workload on primary antioxidants, allowing them to last longer. Together, they provide comprehensive protection.

This synergy has been demonstrated in multiple studies. For instance, a 2019 paper in Journal of Vinyl & Additive Technology showed that combining 0.1% DLTP with 0.2% Irganox 1010 extended the induction period of polypropylene by over 40% compared to using either alone.

Here’s a side-by-side comparison of DLTP and a common primary antioxidant:

Feature	DLTP	Irganox 1010
Type	Secondary	Primary
Mechanism	Peroxide decomposition	Free radical scavenging
Consumption Rate	Low	High
Volatility	Low	Very low
Synergy Potential	High	High
Recommended Use	With primary antioxidants	With secondary antioxidants

Dosage and Processing Tips

Using DLTP effectively requires understanding the right dosage and processing conditions. Too little, and you won’t see much benefit. Too much, and you risk blooming (where the additive migrates to the surface) or unnecessary cost increases.

Here are some general guidelines:

Typical Dosage Range:

Polyolefins: 0.05–0.3%
PVC: 0.1–0.5%
Rubber: 0.2–1.0%

These values may vary depending on the base resin, processing temperature, and expected service life.

Processing Considerations:

Uniform Mixing: DLTP should be evenly distributed in the polymer matrix. Poor dispersion can lead to localized degradation.
Avoid Excessive Heat: While DLTP is heat-stable, excessive temperatures (>220°C) may reduce its efficiency.
Storage Conditions: Store DLTP in a cool, dry place away from direct sunlight and oxidizing agents.

One practical tip: consider using masterbatches—pre-mixed concentrates of DLTP in a carrier resin—to simplify dosing and improve dispersion.

Environmental and Safety Profile

DLTP is generally considered safe for industrial use. It’s non-toxic, non-corrosive, and doesn’t emit harmful fumes under normal processing conditions. However, like any chemical, it should be handled with care.

Here’s a quick safety profile:

Parameter	Result
LD₅₀ (oral, rat)	>2000 mg/kg
Skin Irritation	Mild
Eye Irritation	Moderate
Flammability	Non-flammable
Ecotoxicity	Low

DLTP is approved by regulatory bodies such as the U.S. Food and Drug Administration (FDA) for use in food-contact applications, though it’s typically limited to indirect contact.

From an environmental standpoint, DLTP breaks down slowly in soil and water, so proper disposal is recommended. Some studies suggest microbial degradation pathways, but more research is needed to assess its long-term ecological impact.

Real-World Case Studies

To illustrate DLTP’s effectiveness, let’s look at a couple of real-world case studies.

Case Study 1: Automotive Bumper Material

An automotive supplier was experiencing premature cracking in bumper covers made from polypropylene. Initial analysis revealed signs of oxidative degradation due to prolonged exposure to engine heat.

Solution: The formulation was modified to include 0.15% DLTP along with 0.2% Irganox 1010.

Result: After six months of field testing, no cracks were observed. Accelerated aging tests confirmed a 30% improvement in thermal stability.

Case Study 2: Agricultural Mulch Films

Farmers reported frequent tearing of mulch films used in greenhouse agriculture. The films were made from linear low-density polyethylene (LLDPE).

Investigation: Exposure to sunlight and high temperatures led to rapid oxidation.

Improvement: DLTP was added at 0.2% concentration.

Outcome: Film lifespan increased from 6 months to over 12 months. Farmers reported fewer replacements and higher crop yields due to improved soil moisture retention.

These examples highlight how a relatively small change in formulation can yield significant improvements in product performance.

Challenges and Limitations

Despite its many advantages, DLTP isn’t a magic bullet. Like all additives, it has limitations:

1. Limited UV Protection

DLTP doesn’t absorb UV radiation. If the application involves outdoor exposure, additional UV stabilizers like HALS (hindered amine light stabilizers) are necessary.

2. Potential for Bloom

At high concentrations, DLTP may migrate to the surface of the plastic, forming a waxy layer. This can affect aesthetics and adhesion in painted or printed surfaces.

3. Odor Issues

DLTP has a slight sulfur-like odor, which may be undesirable in sensitive applications like medical devices or children’s toys.

4. Not Suitable for All Polymers

While DLTP works well in polyolefins and PVC, its effectiveness can vary in engineering plastics like polycarbonate or nylon. Always test compatibility before large-scale production.

Future Outlook and Research Trends

As sustainability becomes increasingly important, researchers are exploring ways to enhance the performance of antioxidants while minimizing environmental impact.

Some promising trends include:

Nanoencapsulation of DLTP: Encapsulating DLTP in nanoparticles could improve dispersion and reduce blooming issues.
Bio-based Thioesters: Efforts are underway to develop renewable alternatives to DLTP derived from plant oils.
Synergistic Blends: Combining DLTP with other functional additives (e.g., UV absorbers, flame retardants) to create multifunctional systems.
Computational Modeling: Using machine learning to predict optimal antioxidant combinations for specific applications.

A recent review in Green Chemistry Letters and Reviews (Wang et al., 2021) highlighted the potential of green chemistry approaches in developing next-generation antioxidants that retain the performance of DLTP while improving eco-profiles.

Conclusion: DLTP – The Quiet Protector of Plastics

In the grand theater of plastics, DLTP may not have the flashiest role, but it’s undeniably vital. As a secondary antioxidant, it quietly goes about its business, neutralizing threats before they escalate. Paired with primary antioxidants, it forms a powerful defense system that extends the lifespan of countless plastic products—from humble grocery bags to critical automotive components.

Its versatility, cost-effectiveness, and compatibility make DLTP a favorite among formulators. And while it has its limitations, ongoing research promises to expand its capabilities even further.

So the next time you marvel at the durability of a plastic part or enjoy the convenience of a food package that stays fresh for weeks, remember: somewhere inside, DLTP is working hard to keep things stable, strong, and safe.

References

Zhang, Y., Liu, H., & Wang, J. (2018). "Thermal and oxidative stability of HDPE stabilized with DLTP." Polymer Degradation and Stability, 154, 123–130.
Tanaka, K., Yamamoto, T., & Sato, M. (2016). "Effect of thioester antioxidants on the aging resistance of natural rubber." Journal of Applied Polymer Science, 133(15), 43456.
Lee, C., Kim, S., & Park, J. (2019). "Synergistic effects of DLTP and Irganox 1010 in polypropylene." Journal of Vinyl & Additive Technology, 25(S1), E1–E8.
Wang, X., Zhao, L., & Chen, R. (2021). "Green antioxidants for sustainable plastics: Current status and future perspectives." Green Chemistry Letters and Reviews, 14(3), 210–225.
Smith, P., Brown, T., & Johnson, M. (2020). "Antioxidant performance in polyolefin cable insulation." IEEE Transactions on Dielectrics and Electrical Insulation, 27(2), 567–574.
European Chemicals Agency (ECHA). (2022). "DLTP – Substance Information."
U.S. Food and Drug Administration (FDA). (2021). "Indirect Food Additives: Polymers."

💬 TL;DR: DLTP is a powerful secondary antioxidant that protects plastics from oxidative degradation by neutralizing harmful peroxides. When used with primary antioxidants, it provides long-lasting protection, making it indispensable in industries ranging from packaging to automotive. Despite minor drawbacks, DLTP remains a cost-effective and reliable choice for enhancing the durability of plastic products. 🛡️🧬♻️

If you’d like a printable PDF version or a customized report based on specific applications, feel free to ask!

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Secondary Antioxidant DLTP acts as a potent peroxide decomposer, neutralizing harmful radicals in polymers

DLTP: The Silent Hero Behind Long-Lasting Polymers

When we talk about the longevity and durability of plastics, rubbers, and other polymer materials, one often-overlooked hero works silently behind the scenes — DLTP. Not a household name by any stretch, but this secondary antioxidant plays a crucial role in keeping our everyday plastic goods from turning brittle, discolored, or simply falling apart after a few months under the sun.

So, what exactly is DLTP? Why does it matter so much in the world of polymers? And how does it manage to keep materials looking fresh when exposed to harsh conditions like heat, oxygen, and UV radiation?

Let’s dive into the chemistry, applications, and real-world significance of Dilauryl Thiodipropionate (DLTP) — a compound that might not be on your radar, but definitely deserves a standing ovation in the field of polymer stabilization.

What Is DLTP?

DLTP stands for Dilauryl Thiodipropionate, a chemical compound with the molecular formula C₂₆H₅₀O₄S. It belongs to a class of compounds known as thioesters, which are particularly effective at scavenging harmful peroxides formed during the oxidation of polymers.

Unlike primary antioxidants, which directly intercept free radicals, DLTP acts more like a cleanup crew — decomposing hydroperoxides before they can wreak havoc on polymer chains. This makes DLTP a secondary antioxidant, working in tandem with primary ones like hindered phenols to provide comprehensive protection.

Here’s a quick snapshot of its basic properties:

Property	Value
Molecular Formula	C₂₆H₅₀O₄S
Molecular Weight	474.73 g/mol
Appearance	White to off-white powder or waxy solid
Melting Point	~50–60°C
Solubility in Water	Insoluble
Solubility in Organic Solvents	Soluble in most organic solvents (e.g., ethanol, chloroform)
CAS Number	123-28-4

DLTP is generally non-toxic, making it suitable for use in food packaging and medical-grade plastics — though always within regulated limits, of course.

How DLTP Works: A Tale of Peroxide Decomposition

To understand DLTP’s role, let’s take a step back and look at what happens to polymers over time.

Polymers, especially those based on polyolefins like polyethylene and polypropylene, are prone to oxidative degradation. When exposed to heat, light, or oxygen, they start forming hydroperoxides (ROOH) — unstable molecules that break down into even nastier species: free radicals.

These radicals go on a chain reaction spree, breaking polymer chains and causing all sorts of problems — discoloration, embrittlement, loss of tensile strength, you name it.

Enter DLTP.

DLTP doesn’t stop the initial formation of hydroperoxides, but it decomposes them into harmless products before they can generate dangerous radicals. Think of it as a bomb defusal expert — instead of stopping the bomber, DLTP diffuses the explosive before it goes off.

The general mechanism involves DLTP reacting with ROOH to form stable sulfides and alcohols:

2 ROOH + DLTP → 2 ROH + Oxidized DLTP

This way, the potentially destructive chain reaction is halted at an early stage.

Compared to other secondary antioxidants like Irganox 168 (a phosphite-based stabilizer), DLTP has the advantage of being non-discoloring and less volatile, making it ideal for applications where appearance and long-term stability are key.

Where Is DLTP Used?

DLTP isn’t just some lab experiment — it’s out there, hard at work, in countless industrial and consumer products. Here’s where you’ll find it doing its thing:

1. Polyolefins (PE, PP)

Polyethylene and polypropylene are two of the most widely used plastics in the world. From grocery bags to automotive parts, these materials benefit greatly from DLTP’s protective touch.

Application	Benefit
Food Packaging	Prevents yellowing and odor development
Automotive Components	Enhances thermal aging resistance
Agricultural Films	Delays degradation under sunlight exposure

2. Rubber Compounds

Rubber, whether natural or synthetic, is notoriously sensitive to oxidative degradation. DLTP helps extend the life of rubber hoses, seals, and tires by keeping peroxide levels in check.

3. Adhesives & Sealants

In adhesives, maintaining flexibility and bond strength over time is critical. DLTP ensures that these materials don’t become brittle or lose performance due to oxidative stress.

4. Engineering Plastics

High-performance plastics like nylon and polycarbonate also benefit from DLTP, especially in high-temperature environments such as electronics housings and under-the-hood components.

DLTP vs. Other Secondary Antioxidants

While DLTP is a reliable player in the antioxidant game, it’s not the only one. Let’s compare it with some common alternatives:

Parameter	DLTP	Irganox 168 (Phosphite)	DSTDP
Mechanism	Peroxide decomposer	Hydrolytically unstable phosphite	Similar to DLTP but higher MW
Volatility	Low	Moderate	Low
Discoloration Risk	Very low	Medium (may cause yellowing)	Low
Cost	Moderate	High	High
Recommended Use	General purpose	High-temp processing	Specialty applications

From this table, we can see that DLTP strikes a good balance between cost, effectiveness, and safety. While Irganox 168 is popular for its efficiency in melt processing, it can be prone to hydrolysis and may contribute to color issues. DLTP, on the other hand, is more stable and color-safe, making it a preferred choice for end-use applications rather than processing additives.

Environmental and Safety Considerations

As environmental regulations tighten globally, the sustainability of additives like DLTP becomes increasingly important.

DLTP is generally considered non-toxic and biodegradable, though full degradation depends on environmental conditions. According to data from the OECD guidelines, DLTP shows moderate biodegradability in aquatic environments, typically reaching around 60% degradation within 28 days under optimal conditions.

Property	DLTP
LD₅₀ (rat, oral)	>2000 mg/kg
Ecotoxicity (fish, Daphnia)	Low toxicity
Biodegradability (OECD 301B)	Readily biodegradable (approx. 65%)
Regulatory Status	REACH registered; FDA compliant for food contact (when used within limits)

However, like many industrial chemicals, DLTP should be handled with care. It is not flammable, but prolonged inhalation or skin contact may cause mild irritation. Proper PPE is recommended during handling.

Practical Tips for Using DLTP

Whether you’re a polymer scientist, a process engineer, or a product developer, knowing how to get the most out of DLTP can make a big difference. Here are some practical tips:

Dosage Matters: Typical loading levels range from 0.05% to 1.0% by weight, depending on the polymer type and expected service conditions.
Synergy Works Wonders: Pair DLTP with a primary antioxidant like Irganox 1010 or 1076 for optimal protection. The combination covers both radical interception and peroxide decomposition.
Processing Temperature: DLTP starts to volatilize above 180°C. If you’re running high-temperature extrusion or molding processes, consider adding it later in the mixing cycle.
Storage Conditions: Store DLTP in a cool, dry place away from direct sunlight. Keep containers tightly sealed to prevent moisture absorption.

Case Studies: Real-World Performance

Let’s look at a couple of real-life examples where DLTP made a measurable difference.

Case Study 1: Polypropylene Automotive Parts

A major automotive supplier was experiencing premature cracking in polypropylene dashboard components after only six months of use. Upon investigation, it was found that oxidative degradation had set in due to poor antioxidant formulation.

By incorporating 0.3% DLTP along with 0.15% Irganox 1010, the company saw a 30% improvement in elongation retention after 1000 hours of heat aging at 100°C. The parts maintained their flexibility and showed minimal color change — a win for both performance and aesthetics.

Case Study 2: Agricultural Mulch Film

A manufacturer of black polyethylene mulch film noticed that films stored outdoors began to crack and disintegrate after just one growing season. The culprit? Peroxide buildup accelerated by UV exposure.

Adding 0.2% DLTP to the formulation helped neutralize the peroxides formed during storage and field use. The result was a doubling of service life, with no noticeable decline in mechanical properties.

Future Outlook: What Lies Ahead for DLTP?

Despite the rise of newer antioxidant technologies — including nano-additives and bio-based stabilizers — DLTP remains a staple in the polymer industry. Its proven track record, compatibility with various resins, and relatively low cost ensure that it will continue to play a vital role for years to come.

That said, researchers are exploring ways to enhance DLTP’s performance further. For instance, microencapsulation techniques are being tested to improve dispersion and reduce volatility during processing. Others are blending DLTP with UV absorbers and metal deactivators to create multifunctional additive packages.

There’s also growing interest in developing green alternatives inspired by DLTP’s structure, using renewable feedstocks like plant-derived fatty acids.

Final Thoughts

DLTP may not be a glamorous molecule, but it’s one that quietly ensures the reliability of the plastics we rely on every day. Whether it’s protecting your car bumper from fading, keeping your yogurt container from going stale, or ensuring your garden hose lasts another summer — DLTP is likely playing a part.

It’s a reminder that sometimes, the unsung heroes of science are the ones that make modern life possible without ever demanding attention. So next time you pick up a plastic bottle or admire a shiny dashboard, give a silent nod to DLTP — the tireless warrior against oxidation.

And if you’re a polymer professional, maybe consider giving DLTP a second glance. You might just find it’s the missing piece in your formulation puzzle.

References

George, G., "Antioxidants in Polymer Stabilization", Journal of Applied Polymer Science, Vol. 89, No. 1, pp. 1–10, 2003.
Zweifel, H., Plastics Additives Handbook, 6th Edition, Hanser Gardner Publications, 2009.
Ranby, B.G., Rabek, J.F., Photodegradation, Photo-Oxidation and Photostabilization of Polymers, John Wiley & Sons, 1975.
OECD Guidelines for the Testing of Chemicals, Test Guideline 301B: Ready Biodegradability – CO₂ Evolution Test, 2010.
Wang, Y., et al., “Thermal Stability and Antioxidant Efficiency of Dilauryl Thiodipropionate in Polyolefins”, Polymer Degradation and Stability, Vol. 96, Issue 7, pp. 1345–1352, 2011.
Smith, R.L., “Secondary Antioxidants: Their Role and Synergistic Effects”, Plastics Engineering, Vol. 68, No. 4, pp. 32–37, 2012.
Liu, J., et al., “Performance Evaluation of DLTP in Natural Rubber Vulcanizates”, Rubber Chemistry and Technology, Vol. 88, No. 2, pp. 201–212, 2015.
European Chemicals Agency (ECHA), “REACH Registration Dossier for DLTP”, 2020.
FDA Code of Federal Regulations Title 21, Section 178.2010 – Antioxidants, 2021.
Patel, N.K., “Advances in Antioxidant Technologies for Sustainable Polymers”, Green Materials, Vol. 5, Issue 3, pp. 189–202, 2017.

💬 TL;DR: DLTP is the quiet guardian of polymer integrity — decomposing harmful peroxides, extending product lifespan, and working invisibly to keep your plastics strong and beautiful.

Sales Contact：[email protected]

Understanding the low volatility and high compatibility of Secondary Antioxidant DLTP with various resins

Understanding the Low Volatility and High Compatibility of Secondary Antioxidant DLTP with Various Resins

In the world of polymer chemistry, antioxidants play a role similar to that of sunscreen in skincare — they protect materials from degradation caused by oxidative stress. Among these, secondary antioxidants are like the unsung heroes, working quietly behind the scenes to ensure long-term stability. One such compound, DLTP (Dilauryl Thiodipropionate), stands out for its unique combination of low volatility and high compatibility across a wide range of resins.

If you’re a formulator or a polymer engineer, you might already be familiar with DLTP’s reputation as a reliable processing stabilizer. But what makes it so special? Why does it perform so well where others falter? In this article, we’ll dive deep into the molecular magic of DLTP, exploring its chemical structure, thermal behavior, compatibility with various resins, and real-world applications. Along the way, we’ll also compare it with other common secondary antioxidants and take a look at recent research findings from both domestic and international sources.

What is DLTP?

DLTP, short for Dilauryl Thiodipropionate, is a thioester-based secondary antioxidant. Its full IUPAC name is bis(12-mercaptododecyl) sulfide di(propionate), though most people just stick to DLTP for simplicity.

Here’s a quick snapshot:

Property	Value
Molecular Formula	C₂₈H₅₄O₄S
Molecular Weight	494.78 g/mol
Appearance	White to off-white crystalline powder
Melting Point	~50°C
Boiling Point	>300°C
Solubility in Water	Insoluble
Volatility (at 200°C)	Very low
CAS Number	110-86-1

DLTP belongs to the family of thioesters, which are known for their ability to scavenge peroxides — the primary culprits behind oxidative degradation in polymers. Unlike primary antioxidants (such as hindered phenols), which act by donating hydrogen atoms to free radicals, DLTP functions by decomposing hydroperoxides before they can initiate chain reactions.

The Science Behind Low Volatility

Volatility is one of the key concerns when choosing an antioxidant for high-temperature processing applications. If an antioxidant evaporates too easily during extrusion or molding, it not only reduces effectiveness but can also cause issues like plate-out or odor problems.

DLTP shines in this department due to its high molecular weight and strong intermolecular forces. Let’s break it down:

High Molecular Weight: At nearly 500 g/mol, DLTP is significantly heavier than many other antioxidants. This means it has less tendency to escape into the vapor phase.
Polar Groups: The ester and sulfide groups contribute to stronger dipole-dipole interactions, further lowering vapor pressure.
Thermal Stability: Studies have shown that DLTP remains stable up to temperatures around 250°C, making it ideal for processes like polyolefin extrusion and injection molding.

To put this into perspective, here’s a comparison of volatilities among several common antioxidants at 200°C:

Antioxidant	Volatility Loss (%) at 200°C	Approx. Boiling Point
DLTP	<2%	>300°C
Irganox 1010 (primary)	~8%	~290°C
DSTDP	~15%	~270°C
TNP	~20%	~250°C

As you can see, DLTP is the clear winner when it comes to staying put under heat.

Compatibility: The Secret Sauce

Compatibility is another critical factor in selecting an antioxidant. A poorly compatible additive can bloom to the surface, create haze, or even weaken the mechanical properties of the final product. DLTP, however, is remarkably versatile.

Why? Because of its semi-polar nature. The molecule contains both nonpolar lauryl chains and polar sulfide/ester groups, allowing it to interact favorably with both polar and nonpolar resins.

Let’s explore how DLTP performs in different resin systems:

1. Polyolefins (PE, PP)

Polyolefins are some of the most widely used plastics globally. They’re generally nonpolar, and DLTP blends right in thanks to its long alkyl chains.

Resin Type	Compatibility	Notes
HDPE	Excellent	No blooming, good dispersion
LDPE	Excellent	Often used in film applications
PP	Good–Excellent	Slight migration possible in thick sections

A 2021 study published in Polymer Degradation and Stability found that DLTP showed minimal migration in PP samples aged at 80°C over six months, demonstrating superior long-term compatibility compared to other thioesters.

2. Engineering Plastics (PA, PET, PBT)

These resins are more polar and often processed at higher temperatures. DLTP still holds its own.

Resin Type	Compatibility	Notes
PA6	Good	Works best with synergists like copper inhibitors
PET	Moderate–Good	Some volatility observed above 270°C
PBT	Excellent	Frequently used in automotive components

Researchers at the University of Tokyo noted in a 2022 paper that DLTP, when combined with phosphite antioxidants, provided excellent protection against color formation in PBT compounds during prolonged exposure to heat.

3. Rubbers and Elastomers

DLTP is also popular in rubber formulations, especially where low volatility is essential.

Rubber Type	Compatibility	Notes
EPDM	Excellent	Used in weather-stripping and seals
NBR	Good	May require co-stabilizers
SBR	Good	Effective in tire sidewall compounds

One notable advantage in rubber is that DLTP doesn’t interfere with vulcanization, unlike some other sulfur-containing additives.

Synergies and Stabilization Mechanisms

DLTP rarely works alone. It’s often used in conjunction with primary antioxidants and other secondary stabilizers to provide comprehensive protection.

Here’s a typical stabilization system in polyolefins:

Additive	Role
DLTP	Peroxide decomposer (secondary)
Irganox 1010	Radical scavenger (primary)
Irgafos 168	Phosphite co-stabilizer

This trio works like a dream team:

Primary antioxidants stop radicals in their tracks.
DLTP disarms dangerous peroxides before they become radical generators.
Phosphites neutralize acidic species formed during degradation.

The result? A highly stable material that resists yellowing, embrittlement, and loss of mechanical strength.

Real-World Applications

DLTP isn’t just a lab curiosity — it’s widely used in practical applications across industries. Here are a few examples:

1. Packaging Films

In food packaging, clarity and safety are paramount. DLTP’s low volatility ensures that no harmful residues are left behind after processing. Plus, it helps maintain optical clarity over time.

2. Automotive Components

From dashboards to under-the-hood parts, DLTP protects engineering plastics from thermal degradation. Its compatibility with glass-filled systems is particularly valuable in structural components.

3. Wire and Cable Insulation

In electrical applications, long-term stability is crucial. DLTP helps prevent insulation breakdown caused by oxidation, extending the life of cables.

4. Recycled Plastics

With the rise of circular economy initiatives, DLTP has found a new niche in recycled materials. These materials often come with residual contaminants and degraded structures, and DLTP helps stabilize them during reprocessing.

Environmental and Safety Considerations

While DLTP is generally considered safe, it’s always wise to follow proper handling procedures.

Parameter	Value
Oral LD₅₀ (rat)	>2000 mg/kg
Skin Irritation	Non-irritating
Biodegradability	Moderate
RoHS Compliance	Yes
REACH Registration	Yes

According to a 2023 report by the European Chemicals Agency (ECHA), DLTP poses no significant risk to human health or the environment when used according to guidelines. However, as with any chemical, good industrial hygiene practices should be followed.

Comparative Analysis with Other Thioesters

DLTP isn’t the only thioester antioxidant on the market. Let’s compare it with a few others:

Feature	DLTP	DSTDP	DMTDP	DTDP
Volatility	Very Low	Moderate	Moderate	High
Compatibility	Wide	Narrower	Narrower	Narrow
Cost	Moderate	Lower	Higher	Lower
Thermal Stability	High	Moderate	High	Moderate
Common Use	Polyolefins, rubbers, films	PVC, oils	Specialty polymers	Lubricants, greases

DLTP strikes a balance between performance and cost-effectiveness, making it a go-to choice for many processors.

Recent Research Highlights

Let’s take a moment to spotlight some of the latest studies involving DLTP:

2024 – Zhang et al., China University of Petroleum: Investigated DLTP’s performance in recycled polyethylene terephthalate (rPET). Found that DLTP significantly improved melt stability and reduced acetaldehyde content, a major concern in food-grade rPET.
2023 – Kim et al., Seoul National University: Studied the effect of DLTP on UV-induced degradation of polycarbonate. While PC typically requires UV absorbers, adding DLTP helped reduce yellowing and maintained impact strength better than without.
2022 – Rossi et al., Politecnico di Milano: Compared the migration behavior of various antioxidants in flexible PVC. DLTP was among the least migratory, showing promise for use in medical tubing and flooring.

These studies highlight DLTP’s adaptability and ongoing relevance in modern polymer science.

Conclusion: DLTP — The Quiet Hero of Polymer Stabilization

In the vast landscape of polymer additives, DLTP may not grab headlines like some flashy new hindered amine light stabilizer (HALS), but it deserves recognition for its quiet reliability. With its low volatility, broad compatibility, and proven track record, DLTP continues to be a staple in countless formulations worldwide.

Whether you’re manufacturing food packaging, automotive parts, or industrial cables, DLTP offers a solid foundation for long-term performance. And with increasing emphasis on sustainability and recyclability, its role is likely to grow even more important in the years ahead.

So next time you’re fine-tuning a formulation, don’t overlook this unassuming yet powerful antioxidant. After all, sometimes the best protection is the kind you don’t even notice — until you really need it.

References

Zhang, L., Wang, H., & Liu, Y. (2024). "Stabilization of Recycled PET Using DLTP and Its Impact on Acetaldehyde Content." Journal of Applied Polymer Science, 141(12), 50234.
Kim, J., Park, S., & Lee, K. (2023). "Antioxidant Effects on UV Degradation of Polycarbonate." Polymer Testing, 115, 107982.
Rossi, F., Bianchi, M., & Conti, G. (2022). "Migration Behavior of Antioxidants in Flexible PVC: A Comparative Study." European Polymer Journal, 178, 111520.
ECHA (2023). REACH Registration Dossier for Dilauryl Thiodipropionate. European Chemicals Agency.
Li, X., Chen, Z., & Sun, W. (2021). "Long-Term Thermal Stability of Polypropylene Stabilized with DLTP and Phosphites." Polymer Degradation and Stability, 189, 109567.
University of Tokyo, Department of Materials Science (2022). Annual Report on Polymer Additives in Engineering Thermoplastics.

💬 TL;DR: DLTP is a versatile, low-volatility secondary antioxidant with excellent compatibility across resins. Whether you’re stabilizing polyolefins, engineering plastics, or recycled materials, DLTP delivers consistent performance without the drama. 🧪✨

Sales Contact：[email protected]

Secondary Antioxidant DLTP improves the long-term thermal aging performance of polymers by inhibiting oxidation

DLTP: The Unsung Hero of Polymer Longevity – A Deep Dive into Its Role as a Secondary Antioxidant

Introduction: Aging Gracefully in the World of Polymers

Polymers are everywhere. From your smartphone case to the dashboard of your car, from food packaging to medical devices—polymers have quietly become the backbone of modern life. But like all good things, they don’t last forever. Over time, especially when exposed to heat and oxygen, polymers begin to degrade. This degradation is not just a matter of aesthetics; it can lead to serious performance issues, safety concerns, and economic losses.

Enter DLTP (Dilauryl Thiodipropionate), a secondary antioxidant that might not be a household name but plays a starring role in keeping polymers young and strong for longer. In this article, we’ll take a deep dive into what DLTP does, how it works, and why it’s so important in the world of polymer science. Along the way, we’ll sprinkle in some chemistry, throw in a few tables for clarity, and even add a dash of humor because, let’s face it, talking about oxidation isn’t exactly a laugh riot—but it doesn’t have to be dry either 😄.

What Is DLTP? A Closer Look at the Molecule Behind the Magic

DLTP stands for Dilauryl Thiodipropionate, which sounds like something you’d find on the periodic table after a long night of studying organic chemistry. But in reality, it’s a relatively simple molecule with a powerful function.

Chemical Structure and Properties

DLTP belongs to a class of compounds known as thioesters, which are known for their ability to scavenge free radicals—those pesky little troublemakers responsible for oxidative degradation in polymers. Here’s a quick breakdown:

Property	Value / Description
Chemical Formula	C₂₈H₅₄O₄S
Molecular Weight	502.78 g/mol
Appearance	White to light yellow solid
Melting Point	~45–55°C
Solubility in Water	Insoluble
Compatibility with Polymers	High compatibility with polyolefins, PVC, rubber
Volatility	Low

DLTP works by acting as a hydroperoxide decomposer—in other words, it neutralizes the harmful byproducts of oxidation before they can wreak havoc on polymer chains. Unlike primary antioxidants (like hindered phenols) that directly intercept free radicals, DLTP plays a supporting role, hence its classification as a secondary antioxidant.

The Oxidation Saga: Why Polymers Age and How DLTP Fights Back

Let’s imagine oxidation as a slow-motion horror movie playing out inside your plastic chair or car tire. It starts innocently enough—with heat and oxygen sneaking in where they shouldn’t. Then come the free radicals, attacking polymer chains like wolves tearing through a fence. The result? Chain scission, crosslinking, discoloration, embrittlement, and eventually failure.

But here comes DLTP, wearing a cape made of sulfur atoms (well, metaphorically speaking). Instead of fighting the radicals head-on like primary antioxidants, DLTP takes a subtler approach—it breaks down the hydroperoxides formed during oxidation into harmless products.

This is crucial because hydroperoxides are like ticking time bombs. Left unchecked, they decompose into more free radicals, continuing the cycle of destruction. By stopping them early, DLTP helps extend the polymer’s service life significantly.

Mechanism of Action: The Chemistry Behind the Calm

DLTP works via a thiol-ester exchange reaction, where it reacts with hydroperoxides to form stable sulfones and alcohols. The simplified reaction looks like this:

ROOH + DLTP → ROH + Sulfone derivative

In layman’s terms: DLTP sacrifices itself to save the polymer, much like a loyal sidekick in an action movie 🎬.

Why DLTP Stands Out Among Secondary Antioxidants

There are several secondary antioxidants used in polymer processing—among them, Irganox PS, DOPT, and TNP. But DLTP holds its own for several reasons:

Low Volatility: Unlike some antioxidants that evaporate easily under high processing temperatures, DLTP stays put.
Excellent Compatibility: DLTP blends well with most common polymers, especially polyolefins and PVC.
Cost-Effectiveness: Compared to other secondary antioxidants, DLTP offers a great balance between performance and price.
Thermal Stability: It remains effective even at elevated temperatures, making it ideal for long-term thermal aging protection.

Here’s a comparison table for clarity:

Parameter	DLTP	DOPT	Irganox PS
Molecular Weight	502.78 g/mol	530.86 g/mol	396.62 g/mol
Melting Point	45–55°C	60–70°C	80–90°C
Volatility	Low	Moderate	Low
Cost (approx.)	$10–15/kg	$15–20/kg	$20–25/kg
Compatibility	High	Moderate	High
Typical Use Level (%)	0.05–0.5	0.1–0.3	0.05–0.2

As you can see, DLTP strikes a nice middle ground between volatility, cost, and effectiveness.

Applications Across Industries: Where Does DLTP Shine Brightest?

DLTP may not be a celebrity antioxidant, but it’s definitely a workhorse. Here are some key industries where DLTP plays a vital role:

1. Automotive Industry

In automotive parts such as hoses, seals, and interior trim, exposure to heat and sunlight can accelerate aging. DLTP helps maintain flexibility and prevents cracking over time.

2. Packaging Industry

Polymer films used in food packaging must remain durable and odorless. DLTP ensures that materials like polyethylene stay fresh—not just the food inside, but the packaging itself!

3. Electrical and Electronics

From wire insulation to housing components, DLTP protects against thermal degradation, ensuring long-term reliability and safety.

4. Medical Devices

Medical-grade polymers need to withstand sterilization processes without breaking down. DLTP helps maintain structural integrity and biocompatibility.

5. Construction Materials

PVC pipes, roofing membranes, and outdoor furniture benefit greatly from DLTP’s protective effects, especially in hot climates.

Performance in Long-Term Thermal Aging: Numbers Don’t Lie

To understand how effective DLTP is in real-world conditions, let’s look at some test data from accelerated aging studies.

Test Conditions:

Temperature: 100°C
Duration: 1000 hours
Base polymer: Polypropylene
Additives: Control vs. 0.2% DLTP

Property	Control Sample	With 0.2% DLTP	% Improvement
Tensile Strength (MPa)	18.5	24.1	+30%
Elongation at Break (%)	120	185	+54%
Color Change (Δb*)	8.2	2.1	-74%
Mass Loss (%)	4.7	1.3	-72%

These results clearly show that even a small addition of DLTP can make a significant difference in maintaining polymer properties over time.

Dosage and Processing Considerations: Less Is More

DLTP is typically added at low concentrations, usually between 0.05% and 0.5% by weight, depending on the polymer type and application. Higher dosages don’t necessarily mean better performance and can sometimes lead to blooming or surface migration.

When incorporating DLTP into polymer formulations, it’s often blended during the compounding stage using twin-screw extruders or internal mixers. Because of its low volatility, DLTP remains stable during processing, minimizing losses due to evaporation.

It also pairs well with primary antioxidants like Irganox 1010 or Irganox 1076, forming a synergistic antioxidant system that provides both immediate and long-term protection.

Safety and Environmental Profile: Green Credentials

DLTP is generally considered safe for industrial use. According to the European Chemicals Agency (ECHA), DLTP is not classified as carcinogenic, mutagenic, or toxic to reproduction (CMR substance).

In terms of environmental impact, DLTP has low water solubility and tends to adsorb onto soil particles, reducing its mobility in aquatic environments. However, as with any chemical additive, proper disposal and waste management practices should always be followed.

Case Studies: Real-World Success Stories

Case Study 1: Automotive Rubber Seals

A major automaker noticed premature cracking in rubber door seals after only two years of service. Upon analysis, it was found that the antioxidant package lacked sufficient secondary protection. After adding 0.3% DLTP to the formulation, the seal life increased by over 50%, with no visible degradation after four years of field testing.

Case Study 2: Agricultural Films

A manufacturer of greenhouse films reported brittleness and reduced lifespan in their products after six months of UV exposure. Incorporating DLTP into the polyethylene film formulation extended the useful life to over 18 months without loss of mechanical strength.

Future Outlook: What’s Next for DLTP?

While DLTP has been around for decades, ongoing research continues to explore new ways to enhance its performance and sustainability. Some recent trends include:

Nanoencapsulation: Encapsulating DLTP in nanocarriers to improve dispersion and controlled release.
Bio-based Alternatives: Investigating renewable sources for thioester antioxidants to reduce reliance on petrochemical feedstocks.
Hybrid Systems: Combining DLTP with UV stabilizers and metal deactivators for multifunctional protection.

One promising study published in Polymer Degradation and Stability (Zhang et al., 2021) explored the synergistic effect of DLTP with graphene oxide in polypropylene composites, showing enhanced thermal stability and mechanical retention after prolonged aging.

Conclusion: DLTP – The Quiet Guardian of Polymer Integrity

In the grand theater of polymer stabilization, DLTP may not grab the spotlight like primary antioxidants do, but its role is no less critical. As a secondary antioxidant, DLTP steps in when the initial line of defense begins to falter, offering long-term protection against the relentless march of oxidation.

With its excellent thermal stability, low volatility, broad compatibility, and proven performance, DLTP remains a go-to solution for formulators across industries. Whether you’re designing a car part, wrapping a sandwich, or building a pacemaker, DLTP helps ensure that the polymer does what it’s supposed to do—without falling apart.

So next time you admire the durability of a plastic component or marvel at the longevity of a rubber seal, remember there’s a quiet hero working behind the scenes—DLTP, the unsung champion of polymer preservation 💪.

References

Zweifel, H., Maier, R. D., & Schiller, M. (2014). Plastics Additives Handbook. Hanser Publishers.
Ranby, B. G., & Rabek, J. F. (1975). Photodegradation, Photooxidation and Photostabilization of Polymers. Wiley.
Gugumus, F. (1998). “Antioxidant systems in polyolefins.” Polymer Degradation and Stability, 62(1), 1–15.
Zhang, Y., Li, X., Wang, Q., & Chen, Z. (2021). “Synergistic effect of DLTP and graphene oxide on the thermal aging resistance of polypropylene.” Polymer Degradation and Stability, 189, 109578.
Luda, M. P., Camino, G., & Costa, L. (2003). “Antioxidants in polymeric materials.” Journal of Analytical and Applied Pyrolysis, 69(1), 1–22.
European Chemicals Agency (ECHA). (2022). "Dilauryl Thiodipropionate (DLTP): Substance Information."
Breuer, O., Sundararaj, U., & Kausch, H. H. (2004). “Stress relaxation and chain scission in thermally aged polyethylene.” Polymer Engineering & Science, 44(5), 953–961.
Pospíšil, J., & Nešpůrek, S. (2000). “Prevention of polymer photoaging by antioxidant additives.” Progress in Polymer Science, 25(8), 1093–1139.

If you’d like me to expand any section further, turn this into a presentation, or tailor it for a specific industry, feel free to ask!

Sales Contact：[email protected]

Antioxidant 1790 for wire and cable compounds, ensuring enhanced electrical insulation and physical durability

Antioxidant 1790 for Wire and Cable Compounds: The Silent Guardian of Electrical Reliability

Introduction: A Quiet Hero in a Noisy World

In the world of wire and cable manufacturing, where voltage runs high and expectations run even higher, there’s one unsung hero that often flies under the radar — Antioxidant 1790. This unassuming chemical compound may not make headlines or win innovation awards, but it plays a critical role in ensuring that the cables powering our homes, offices, cities, and industries remain safe, efficient, and durable.

Imagine your favorite superhero — but instead of wearing a cape, they wear a lab coat. Instead of battling villains, they battle oxidation. That’s Antioxidant 1790 in a nutshell (or should I say, in a polymer matrix?).

This article dives deep into what makes Antioxidant 1790 such a vital ingredient in modern wire and cable compounds. We’ll explore its chemistry, its performance benefits, real-world applications, and how it stacks up against other antioxidants on the market. Along the way, we’ll sprinkle in some industry insights, data tables, and even a few puns to keep things lively.

Let’s plug into this topic and see why Antioxidant 1790 is more than just an additive — it’s a game-changer.

What Is Antioxidant 1790?

Antioxidant 1790 is a hindered phenolic antioxidant, typically used in polymeric materials to prevent oxidative degradation during processing and long-term use. In simpler terms, it acts like a bodyguard for polymers, protecting them from the damaging effects of heat, oxygen, and UV radiation.

It belongs to the family of phenolic antioxidants, which are known for their excellent thermal stability and compatibility with various polymer matrices. Its full chemical name is usually something along the lines of:

Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)

But unless you’re a chemist or have a particular fondness for tongue-twisters, you can stick with "Antioxidant 1790".

Key Features at a Glance

Feature	Description
Type	Hindered Phenolic Antioxidant
Appearance	White to off-white powder
Molecular Weight	~1180 g/mol
Melting Point	110–125°C
Solubility in Water	Insoluble
Recommended Usage Level	0.1–1.0 phr (parts per hundred resin)
Thermal Stability	High
Compatibility	Excellent with PE, PVC, EVA, PP, etc.

Why Oxidation Matters (Even If You Don’t Think It Does)

Oxidation is the enemy of polymers. Just like apples brown when exposed to air, plastics degrade when they come into contact with oxygen — especially under high temperatures during extrusion or over time in service conditions.

The result? Brittle insulation, reduced mechanical strength, discoloration, and ultimately, failure of the cable system. Not exactly what you want in a power grid or a submarine.

Antioxidants like 1790 work by scavenging free radicals — those pesky reactive molecules that kickstart the chain reaction of oxidation. By interrupting this process, Antioxidant 1790 helps preserve the integrity of the polymer, keeping your cables strong and reliable for years.

Think of it as putting a firewall between your cable and Mother Nature’s mischief.

How Antioxidant 1790 Works: A Molecular Ballet

At the molecular level, Antioxidant 1790 performs a graceful dance with oxygen. When a polymer is subjected to heat or UV light, it generates hydroperoxides, which then decompose into free radicals. These radicals attack neighboring polymer chains, causing crosslinking or chain scission — both of which are bad news for mechanical and electrical properties.

Enter Antioxidant 1790. With its bulky phenolic structure, it donates hydrogen atoms to neutralize these radicals, halting the degradation process in its tracks.

Here’s a simplified version of the mechanism:

ROO• + AH → ROOH + A•
A• + ROO• → non-radical products

Where:

ROO• = Peroxy radical
AH = Antioxidant molecule (Antioxidant 1790)
A• = Stabilized antioxidant radical

Because of its sterically hindered structure, Antioxidant 1790 is particularly effective at resisting further reactions once it has donated its hydrogen atom. This makes it a long-lasting protector — ideal for applications where longevity is key, such as underground cables or aerospace wiring.

Performance Benefits: Why Choose Antioxidant 1790 Over Others?

There are many antioxidants on the market — from Irganox to Ethanox, and everything in between. So what makes Antioxidant 1790 stand out?

Let’s break it down:

1. Superior Thermal Stability

Antioxidant 1790 maintains its effectiveness even at elevated processing temperatures (up to 200°C), making it suitable for demanding extrusion processes.

2. Excellent Color Retention

One of the side effects of oxidation is yellowing or browning of polymers. Antioxidant 1790 helps maintain the original color of the material, which is especially important for consumer-facing cables or industrial cables where visual inspection is part of maintenance.

3. Low Volatility

Unlike some lighter antioxidants, Antioxidant 1790 doesn’t evaporate easily during processing. This ensures consistent protection throughout the product lifecycle.

4. Broad Polymer Compatibility

From polyethylene (PE) to polyvinyl chloride (PVC) and ethylene-vinyl acetate (EVA), Antioxidant 1790 plays well with others. This versatility makes it a go-to choice for multi-purpose cable formulations.

5. Long-Term Durability

Thanks to its robust molecular structure, Antioxidant 1790 provides extended protection, helping cables last 20+ years without significant degradation — a major plus in infrastructure projects.

Comparative Analysis: How Does Antioxidant 1790 Stack Up?

To give you a better sense of where Antioxidant 1790 stands in the antioxidant lineup, let’s compare it with two commonly used alternatives: Irganox 1010 and Antioxidant 1076.

Property	Antioxidant 1790	Irganox 1010	Antioxidant 1076
Chemical Type	Pentaerythritol ester	Pentaerythritol ester	Octadecyl ester
Molecular Weight	~1180	~1180	~531
Melting Point	110–125°C	119–124°C	50–55°C
Volatility	Low	Moderate	High
Thermal Stability	Excellent	Good	Moderate
Migration Resistance	High	Moderate	Low
Cost	Moderate	High	Low
Primary Use	Wires & cables, automotive	General purpose	Packaging, films

As shown in the table above, Antioxidant 1790 holds its own — and often outperforms — other antioxidants in terms of thermal stability and migration resistance. While Irganox 1010 is a popular alternative, its higher cost and moderate volatility make Antioxidant 1790 a more practical choice for long-term applications like wire and cable manufacturing.

Applications in the Real World: From Power Plants to Your Living Room

Antioxidant 1790 isn’t just a lab experiment — it’s hard at work all around us. Here are some of the key areas where it shines:

1. Medium and High-Voltage Power Cables

These cables operate under extreme conditions — high temperatures, constant current flow, and exposure to environmental stressors. Antioxidant 1790 helps maintain insulation integrity, preventing short circuits and reducing fire risks.

2. Automotive Wiring Harnesses

Cars today are packed with electronics — from infotainment systems to advanced driver-assistance features. Antioxidant 1790 ensures that the wiring harnesses remain flexible and functional, even under hood temperatures that can exceed 150°C.

3. Industrial Control Cables

In factories and plants, control cables need to be tough enough to handle vibrations, chemicals, and repeated flexing. Antioxidant 1790 boosts mechanical durability, reducing downtime and maintenance costs.

4. Underground and Submarine Cables

These cables are installed once and expected to last decades. Antioxidant 1790 enhances their longevity, especially in humid or saline environments where degradation accelerates.

5. Consumer Electronics Cables

USB cords, HDMI cables, and charging wires might seem trivial, but they’re subject to frequent bending, temperature fluctuations, and UV exposure. Antioxidant 1790 helps prevent premature cracking and failure — saving consumers from the frustration of yet another broken charger 😤.

Dosage and Formulation Tips: Getting the Most Out of Antioxidant 1790

Using Antioxidant 1790 effectively requires a balance between dosage and formulation. Too little, and you won’t get adequate protection. Too much, and you risk blooming (where the antioxidant migrates to the surface, leaving a white residue).

Here are some general guidelines:

Recommended Loading: 0.2–0.8 parts per hundred resin (phr)
Best Results: Used in combination with a secondary antioxidant (e.g., a phosphite or thioester) for synergistic effect.
Processing Temperature: Ideal for extrusion processes up to 200°C
Storage: Store in a cool, dry place away from direct sunlight

Sample Formulation for Cross-Linked Polyethylene (XLPE) Insulation

Component	Parts per Hundred Resin (phr)
Base XLPE Resin	100
Crosslinking Agent (DCP)	1.0
Silane Coupling Agent	0.5
Antioxidant 1790	0.5
Secondary Antioxidant (e.g., Irgafos 168)	0.3
Fillers (CaCO₃, etc.)	30
Pigments (if needed)	As required

This formulation provides good mechanical strength, excellent thermal aging resistance, and long-term reliability — perfect for high-voltage cable applications.

Case Studies: Real-World Performance

Case Study 1: Underground Power Cable Project in Germany 🇩🇪

In a recent project involving 132 kV underground cables, engineers opted for an XLPE formulation containing 0.6 phr of Antioxidant 1790. After five years of operation, thermal imaging and insulation resistance tests showed no signs of degradation — significantly outperforming previous installations using lower-grade antioxidants.

Case Study 2: Automotive Harness Testing in Japan 🇯🇵

A Japanese Tier 1 supplier conducted accelerated aging tests on automotive wiring harnesses. Those formulated with Antioxidant 1790 showed 20% less tensile strength loss after 1,000 hours at 150°C compared to those without antioxidants. The conclusion? Enhanced long-term reliability and reduced warranty claims.

Case Study 3: Marine Cable Application in Norway 🇳🇴

Subsea cables installed off the coast of Norway were formulated with Antioxidant 1790 to combat saltwater corrosion and UV exposure. Post-installation inspections after three years revealed minimal surface degradation and maintained dielectric properties — proving its resilience in harsh environments.

Environmental and Safety Considerations: Green Credentials

As sustainability becomes a global priority, manufacturers are increasingly scrutinizing the environmental impact of additives. Fortunately, Antioxidant 1790 checks most of the boxes:

Non-Toxic: Classified as non-hazardous under REACH regulations.
Low VOC Emission: Minimal volatile organic compound release during processing.
RoHS Compliant: Meets restrictions on hazardous substances.
Recyclable: Compatible with common polymer recycling streams.

While not biodegradable in the traditional sense, its low migration and stable structure mean it doesn’t leach into the environment easily.

Future Trends and Innovations

The demand for longer-lasting, safer, and more sustainable cables continues to grow. As new materials like bio-based polymers and conductive composites enter the market, the role of antioxidants like 1790 will only become more crucial.

Researchers are also exploring hybrid antioxidant systems — combining Antioxidant 1790 with UV stabilizers and metal deactivators to create multi-functional protective packages. Some labs are even experimenting with nano-enhanced antioxidant delivery systems to improve dispersion and efficiency.

And who knows — maybe someday we’ll see self-healing cables powered by smart antioxidant networks 🤖⚡. But until then, Antioxidant 1790 remains the gold standard.

Conclusion: The Unsung Hero of Modern Infrastructure

In the grand scheme of electrical engineering, Antioxidant 1790 may not grab headlines or win design awards. But behind every reliable cable, every uninterrupted power supply, and every flicker-free lightbulb lies the quiet diligence of this remarkable compound.

From the depths of the ocean to the heart of our cities, Antioxidant 1790 works tirelessly to ensure that the invisible threads of electricity keep flowing — safely, efficiently, and reliably.

So next time you plug in your phone, flip a switch, or ride an electric train, take a moment to appreciate the tiny molecule standing guard inside the insulation. Because without Antioxidant 1790, the lights might just go out sooner than you expect.

💡🔋🔌

References

Smith, J. R., & Lee, H. (2020). Thermal and Oxidative Stability of Polymer-Based Cable Insulation Materials. Journal of Applied Polymer Science, 137(15), 48632.
Tanaka, M., Yamamoto, K., & Nakamura, T. (2019). Long-Term Aging Behavior of XLPE Cables with Different Antioxidant Systems. IEEE Transactions on Dielectrics and Electrical Insulation, 26(3), 789–796.
European Chemicals Agency (ECHA). (2021). REACH Registration Dossier – Antioxidant 1790.
Zhang, Y., Liu, X., & Wang, Q. (2022). Synergistic Effects of Binary Antioxidant Systems in Polyolefin Cables. Polymer Degradation and Stability, 198, 109902.
International Electrotechnical Commission (IEC). (2018). IEC 60502-1: Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1.2 kV) up to 30 kV (Um = 36 kV).
National Fire Protection Association (NFPA). (2020). NFPA 70: National Electrical Code® (NEC®).
Kim, S. J., Park, H. G., & Choi, B. R. (2021). Evaluation of Antioxidant Migration in Automotive Wiring Applications. Macromolecular Research, 29(5), 345–353.
ISO Standard 1817:2022 – Rubber, vulcanized – Determination of resistance to liquid fuels and other fluids.
Gupta, A., & Sharma, R. (2023). Sustainable Additives for Polymer Insulation in Electrical Cables. Advanced Materials and Technologies, 8(2), 112–125.
ASTM D3065-19 – Standard Practice for Sampling and Testing of Antioxidants in Polyolefins.

If you’d like me to generate a printable PDF version or help with technical bulletins, feel free to ask!

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Evaluating the excellent hydrolytic stability and non-staining nature of Primary Antioxidant 1790 across various conditions

The Unstainable Champion: Evaluating the Hydrolytic Stability and Non-Staining Nature of Primary Antioxidant 1790

Introduction

Let’s talk antioxidants—not the kind you sip in your green smoothie, but the ones that keep industrial materials from falling apart under pressure, heat, or time. Among these unsung heroes of polymer chemistry stands Primary Antioxidant 1790, a compound that has quietly built a reputation for itself in the world of plastics, rubbers, and synthetic materials.

Now, before you yawn and reach for your phone, let me tell you—this is not just another chemical name buried in a safety data sheet. This is a story about endurance, resistance to degradation, and staying power. It’s about a molecule that refuses to stain when others can’t help themselves and holds up against water like a duck in a rainstorm.

In this article, we’ll dive deep into two of its most impressive traits:

Hydrolytic stability – how well it resists breaking down in the presence of water or moisture.
Non-staining properties – why it doesn’t leave behind unsightly marks on finished products, which is more important than you might think.

We’ll explore its chemical makeup, test it under various conditions, compare it with other antioxidants, and even peek into some scientific literature (yes, the real stuff published by people who wear lab coats for fun). So grab your coffee, maybe a snack, and let’s take a closer look at what makes Antioxidant 1790 such a standout player in the field of material stabilization.

What Is Primary Antioxidant 1790?

Before we get into the nitty-gritty of hydrolysis and staining, let’s first understand what we’re dealing with here.

Chemical Identity

Primary Antioxidant 1790, also known by its full IUPAC name as Tris(2,4-di-tert-butylphenyl)phosphite, is a member of the phosphite antioxidant family. It’s primarily used as a processing stabilizer in polymers, especially polyolefins like polyethylene and polypropylene. Its structure features three bulky tert-butyl groups attached to phenolic rings, making it quite resistant to thermal and oxidative stress.

Property	Value
Molecular Formula	C₃₃H₅₁O₃P
Molecular Weight	~514.7 g/mol
Appearance	White to off-white powder or granules
Melting Point	~180°C
Solubility in Water	Practically insoluble
CAS Number	31570-04-4

These characteristics make it particularly suitable for high-temperature processing environments where oxidation can wreak havoc on material integrity.

But wait—why do we care so much about hydrolytic stability and non-staining behavior? Let’s find out.

Why Hydrolytic Stability Matters

Imagine a superhero who loses their powers the moment they get wet. That wouldn’t be very useful, would it? In much the same way, an antioxidant that breaks down in the presence of moisture is of limited use in many applications.

What Is Hydrolytic Stability?

Hydrolytic stability refers to a chemical compound’s ability to resist decomposition when exposed to water or humidity. For antioxidants used in outdoor or humid environments—like automotive parts, packaging films, or agricultural films—this is critical. If the antioxidant degrades due to moisture, it can no longer protect the polymer matrix from oxidative degradation.

How Does 1790 Perform?

Thanks to its highly branched, sterically hindered structure, Primary Antioxidant 1790 shows excellent resistance to hydrolysis. The bulky tert-butyl groups act like shields, protecting the phosphite center from nucleophilic attack by water molecules.

Here’s a quick comparison between 1790 and some common antioxidants:

Antioxidant	Hydrolytic Stability	Notes
Irganox 1010	Moderate	Prone to partial hydrolysis over time
Irgafos 168	Good	Slightly better than Irganox, still not top-tier
Primary Antioxidant 1790	Excellent	Outstanding resistance to moisture-induced breakdown

A study by Zhang et al. (2018) tested several phosphite antioxidants under accelerated aging conditions involving elevated humidity. They found that 1790 retained over 90% of its original activity after 1000 hours, while Irgafos 168 dropped below 70%.

“The steric hindrance provided by the tert-butyl groups significantly improves the durability of 1790 under moist conditions.” — Zhang et al., Journal of Applied Polymer Science, 2018

The Stain Test: Non-Staining Properties Explained

Now, let’s talk about aesthetics. Because if your white plastic chair turns yellow or develops mysterious brown spots after a few months outdoors, no one cares how stable the antioxidant was—it looks bad, and people won’t buy it.

What Causes Staining?

Staining typically occurs when antioxidants or their degradation products migrate to the surface of the polymer and react with light, oxygen, or metal ions. These reactions can form colored compounds, often resulting in undesirable discoloration.

Common culprits include:

Phenolic antioxidants (e.g., BHT)
Certain types of hindered amine light stabilizers (HALS)
Some phosphonites and phosphites with less steric protection

Why Doesn’t 1790 Stain?

Because of its large molecular size and low volatility, 1790 has minimal tendency to bloom to the surface. Moreover, its degradation products are colorless and do not react strongly with metal ions or UV radiation.

To put it simply: it does its job without leaving behind any evidence. Like a ninja.

Let’s see how it stacks up:

Antioxidant	Staining Tendency	Visual Impact After Aging
Irganox 1076	Moderate	Slight yellowing
Irgafos 168	Low-Moderate	Occasional blooming and minor discoloration
Primary Antioxidant 1790	Very Low	No visible change after 500 hours UV exposure

A comparative evaluation by Tanaka & Lee (2020) showed that films containing 1790 exhibited no detectable discoloration after 1000 hours of xenon arc lamp exposure, whereas those with Irgafos 168 showed faint yellowing.

“The absence of chromophoric degradation products makes 1790 ideal for clear or light-colored applications.” — Tanaka & Lee, Polymer Degradation and Stability, 2020

Real-World Performance Across Conditions

So far, we’ve established that 1790 is tough against water and plays nice with colors. But how does it hold up in the wild—under different temperatures, pressures, and environmental stresses?

Thermal Stability

One of the key concerns during polymer processing is thermal degradation. High-temperature extrusion or injection molding can break down additives if they aren’t up to the task.

1790 shines here too. With a melting point around 180°C, it remains stable during most standard processing operations. Even under prolonged heating at 220°C, studies show minimal decomposition.

Temperature	Residual Activity After 24 hrs (%)
180°C	98%
200°C	95%
220°C	90%

This makes it suitable for both PP and HDPE applications, where processing temperatures often hover between 190–230°C.

Humidity Resistance

As previously mentioned, 1790 is remarkably stable under humid conditions. This is especially important for applications like agricultural films, outdoor furniture, and automotive interiors, where condensation and dampness are everyday realities.

A 2021 study by Chen & Patel evaluated antioxidant performance under 85% relative humidity at 85°C (known as the "85/85" test condition). Here’s what they found:

Additive	Mass Loss After 1000 Hours	Color Change (ΔE)
Irganox 1010	12%	ΔE = 4.2
Irgafos 168	8%	ΔE = 2.1
Primary Antioxidant 1790	2%	ΔE = 0.3

That last row should make you smile. Almost no mass loss, almost no color change. That’s the kind of consistency that earns respect in the industry.

Compatibility and Application Scope

Another factor that determines the usefulness of an antioxidant is its compatibility with other additives and base polymers.

Polymer Compatibility

1790 works well with:

Polyethylene (PE)
Polypropylene (PP)
Polystyrene (PS)
ABS (Acrylonitrile Butadiene Styrene)

It also synergizes nicely with secondary antioxidants like Irganox 1010 or Irganox 1098, offering dual-layer protection against oxidative degradation.

Additive Synergy

When combined with HALS (hindered amine light stabilizers), 1790 enhances long-term UV resistance. Unlike some phosphites that can interfere with HALS efficiency, 1790 maintains good synergy.

System	UV Resistance (hrs to failure)
HALS Only	800
HALS + Irgafos 168	1000
HALS + 1790	1200

Source: Wang et al., Plastics Additives and Modifiers Handbook, 2019

This means that formulations using 1790 can go longer without showing signs of embrittlement, cracking, or fading—especially important for outdoor applications.

Environmental and Regulatory Considerations

With increasing scrutiny on chemical additives, it’s essential to consider the environmental profile and regulatory status of any widely used compound.

Toxicity and Safety

According to the European Chemicals Agency (ECHA) database, 1790 is classified as non-hazardous under current REACH regulations. It shows low acute toxicity and does not bioaccumulate in aquatic organisms.

Parameter	Value
LD50 (rat, oral)	>2000 mg/kg
Aquatic Toxicity (LC50, Daphnia)	>100 mg/L
Biodegradability	Poor (but not persistent in environment)

While it isn’t biodegradable, its low leaching tendency reduces environmental exposure risk.

Volatility and Migration

Due to its high molecular weight and low vapor pressure, 1790 exhibits very low volatility, meaning it doesn’t evaporate easily during processing or service life.

Migration tests conducted by Kovács et al. (2022) on food-grade PP containers showed that 1790 remained well within EU migration limits (<10 mg/kg).

Industrial Applications

Let’s now shift gears and look at where exactly 1790 finds its home in the industrial world.

Automotive Industry

From dashboards to bumpers, polymers play a major role in modern vehicles. The combination of heat, UV exposure, and moisture makes this a harsh environment for unprotected plastics.

Using 1790 in interior and exterior components ensures:

Long-term color retention
Resistance to thermal cycling
Reduced risk of blooming or whitening

Packaging Films

Clear, durable packaging films need antioxidants that won’t cloud the appearance or leave stains. 1790 fits the bill perfectly, especially in stretch wrap, shrink film, and food packaging applications.

Agriculture

Greenhouses, mulch films, and irrigation tubing all rely on polymers that must endure years of sun and rain. 1790 helps maintain mechanical strength and clarity without compromising aesthetics.

Consumer Goods

From toys to kitchenware, consumer products demand both safety and longevity. 1790 is frequently used in household items made from polyolefins, ensuring they stay clean, functional, and visually appealing.

Conclusion: The Quiet Guardian of Polymer Integrity

In the grand theater of polymer additives, Primary Antioxidant 1790 may not be the loudest performer, but it’s certainly one of the most reliable. Its exceptional hydrolytic stability ensures that it continues to protect materials even in humid or wet environments. Meanwhile, its non-staining nature keeps products looking fresh and professional—no matter how long they sit in the sun or how much moisture they endure.

Through rigorous testing, scientific validation, and widespread industrial adoption, 1790 has earned its place among the elite class of stabilizers. Whether you’re manufacturing car parts, wrapping groceries, or building backyard furniture, choosing 1790 means choosing peace of mind.

So next time you pick up a white plastic container that hasn’t yellowed after a year outside—or a car bumper that still looks factory-fresh after five years—you might just have Primary Antioxidant 1790 to thank. And while it won’t win any awards for glamour, it will definitely earn your respect—for doing its job quietly, effectively, and without leaving a trace.

References

Zhang, Y., Li, M., & Wang, H. (2018). Hydrolytic Stability of Phosphite Antioxidants in Polyolefin Matrices. Journal of Applied Polymer Science, 135(21), 46234.
Tanaka, K., & Lee, J. (2020). Discoloration Mechanisms in Stabilized Polymers. Polymer Degradation and Stability, 173, 109087.
Chen, L., & Patel, R. (2021). Humidity Resistance of Modern Antioxidants in Agricultural Films. Journal of Polymer Engineering, 41(4), 231–240.
Wang, X., Zhao, T., & Kumar, A. (2019). Synergistic Effects of HALS and Phosphite Antioxidants in Outdoor Applications. Plastics Additives and Modifiers Handbook, 45(3), 123–135.
Kovács, G., Novák, Z., & Horváth, P. (2022). Migration Behavior of Antioxidants in Food Contact Polymers. Food Additives & Contaminants, 39(5), 765–778.
European Chemicals Agency (ECHA). REACH Registration Dossier for Tris(2,4-di-tert-butylphenyl)phosphite. ECHA Database, Version 1.2, 2020.

If you’re interested in diving deeper into specific case studies, formulation strategies, or regulatory compliance details, feel free to ask!

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Introduction: A Touch of Science in Everyday Plastics

What Is DLTP? And Why Should You Care?

Chemical Profile of DLTP

Why Molded Articles Need Antioxidants

DLTP’s Role in Enhancing Physical Appearance

1. Color Retention

2. Surface Quality

3. Long-Term Clarity

DLTP and Dimensional Stability: Keeping Things in Shape

1. Reducing Warpage in Injection Molding

2. Controlling Shrinkage and Expansion

3. Resistance to Environmental Stress Cracking

Synergies with Other Additives: Teamwork Makes the Dream Work

Processing Considerations: How Much DLTP Do You Really Need?

Real-World Applications: From Toys to Turbines

1. Consumer Goods – Keeping Kids Happy

2. Automotive – Under the Hood and Beyond

3. Medical Devices – Precision Matters

4. Industrial Equipment – Tough as Nails

Conclusion: DLTP – The Unsung Hero of Plastic Perfection

References

DLTP: The Unsung Hero of Food Safety – A Secondary Antioxidant for Food Contact Applications

What Exactly Is DLTP?

Why Use DLTP in Food Contact Applications?

Regulatory Compliance and Global Standards

Performance Parameters of DLTP

Real-World Applications of DLTP

1. Flexible Packaging Films

2. Food Containers

3. Bottle Caps and Lids

4. Medical Food Packaging

Synergistic Effects with Other Additives

Case Studies and Research Insights

Challenges and Considerations

Future Outlook and Innovations

Conclusion

References

Enhancing the Mechanical Properties and Processability of Recycled Polymers Using Secondary Antioxidant DLTP

Introduction: A Second Life for Plastics

What is DLTP?

Chemical Structure and Properties

The Problem with Recycled Polymers

How DLTP Works: The Science Behind the Magic

Benefits of DLTP in Recycled Polymer Systems

1. Improved Thermal Stability

2. Retention of Mechanical Properties

3. Enhanced Color Stability

4. Better Processability

Comparative Performance with Other Stabilizers

Recommended Dosage and Processing Conditions

Case Studies: Real-World Applications

Case Study 1: Recycling Automotive Bumpers

Case Study 2: Packaging Film Reuse

Environmental and Safety Considerations

Future Outlook and Research Directions

Conclusion: DLTP – The Unsung Hero of Plastic Recycling

References

Table of Contents

1. What Is DLTP and Why Should You Care?

2. The Science Behind Secondary Antioxidants

Primary vs. Secondary Antioxidants

3. How DLTP Protects Polymers from Yellowing

4. Applications in Film and Fiber Industries

In Film Applications

In Fiber Applications

5. DLTP vs. Other Antioxidants: A Comparative Look

6. Key Technical Parameters of DLTP

7. Environmental and Safety Considerations

8. Case Studies and Real-World Performance

Case Study 1: Polypropylene Shrink Film Manufacturer

Case Study 2: Synthetic Carpet Fiber Producer

Case Study 3: Agricultural Greenhouse Film

9. Future Trends and Innovations

10. Conclusion: DLTP – Small Molecule, Big Impact

References

Introduction: The Silent Guardian of Plastics

What Is DLTP?

Why Do Plastics Need Antioxidants?

How Does DLTP Work?

Advantages of Using DLTP in Plastics