A comparative analysis of Primary Antioxidant 1035 versus other leading phenolic antioxidants for polyolefin applications

A Comparative Analysis of Primary Antioxidant 1035 Versus Other Leading Phenolic Antioxidants for Polyolefin Applications


Introduction: The Unsung Heroes of Polymer Longevity

Imagine a world without plastics. No water bottles, no car bumpers, no food packaging — in short, modern life would be… sticky, to say the least. But as much as we rely on polymers like polyethylene and polypropylene, these materials are not invincible. Left to their own devices, they start to degrade — cracking, yellowing, and losing mechanical strength. Enter antioxidants, the silent guardians that keep our plastics young and strong.

In this article, we dive into one such hero: Primary Antioxidant 1035, often referred to by its chemical name, Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), or simply Irganox 1035 (Ciba’s brand name). We’ll compare it head-to-head with other leading phenolic antioxidants used in polyolefins, including Irganox 1010, Irganox 1076, Ethanox 330, and Sumilizer GP-1. Our goal? To understand which antioxidant brings what to the table, and under what circumstances each might shine brightest.

So, buckle up. It’s time to go behind the molecules.


What Are Phenolic Antioxidants?

Phenolic antioxidants are a class of stabilizers designed to combat oxidative degradation in polymers. They work by scavenging free radicals — those pesky reactive species formed during thermal processing and long-term use — before they can wreak havoc on polymer chains.

The general mechanism is simple yet elegant: the phenolic hydroxyl group (-OH) donates a hydrogen atom to stabilize the radical, effectively breaking the chain reaction of oxidation. This process is known as hydrogen atom transfer (HAT).

Among the many types of antioxidants — phosphites, thioesters, hindered amines — phenolics stand out as primary antioxidants, meaning they’re typically the first line of defense against oxidation.

Now, let’s meet the contenders.


Meet the Contenders: A Roster of Radical Scavengers

Below is a quick introduction to the major players in the phenolic antioxidant arena:

Name Chemical Structure Brand Names Molecular Weight Melting Point (°C) Key Features
Antioxidant 1035 Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) Irganox 1035 ~1180 g/mol 52–57 Excellent volatility resistance, high molecular weight
Antioxidant 1010 Same structure as 1035 but with ester linkages Irganox 1010 ~1180 g/mol 119–125 High performance, widely used, good color retention
Antioxidant 1076 Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate Irganox 1076 ~531 g/mol 50–55 Low volatility, excellent compatibility
Ethanox 330 Tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate Ethanox 330 ~699 g/mol 200–205 High temperature stability, low migration
Sumilizer GP-1 Bis(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate Sumilizer GP-1 ~570 g/mol 140–145 Unique phosphorus-containing structure, dual function

Let’s now take a closer look at each of them, especially focusing on how Antioxidant 1035 stacks up.


Antioxidant 1035: The Tetrakis Wonder

Antioxidant 1035 is a tetrafunctional hindered phenolic antioxidant, meaning it has four active phenolic groups per molecule. This gives it a significant advantage in terms of radical scavenging efficiency.

Its core structure is based on pentaerythritol, a tetra-alcohol that acts as a central scaffold for four phenolic esters. This design leads to several important properties:

  • High molecular weight: Reduces volatility and migration.
  • Excellent thermal stability: Ideal for high-temperature processing.
  • Low extractability: Stays put in the polymer matrix.
  • Good color retention: Helps maintain product aesthetics.

It is commonly used in polyolefins, especially polyethylene (PE) and polypropylene (PP), where long-term thermal aging resistance is crucial.

Typical Use Levels

Application Recommended Level (pph*)
Polyethylene 0.05–0.2
Polypropylene 0.1–0.3
Films & fibers 0.05–0.15
Molded parts 0.1–0.2

* pph = parts per hundred resin


Head-to-Head Comparison: How Does 1035 Stack Up?

Let’s break down the competition across key performance indicators.

1. Volatility and Migration

One of the biggest challenges in antioxidant selection is ensuring that the additive stays within the polymer over time. Volatile antioxidants can escape during processing or through prolonged exposure to heat or solvents.

Antioxidant Volatility (mg/g @ 150°C, 24 hrs) Migration (in water/oil)
1035 ~0.5 Very low
1010 ~1.2 Moderate
1076 ~2.0 High
Ethanox 330 ~0.8 Low
GP-1 ~1.0 Moderate

As shown above, Antioxidant 1035 shines in low volatility and minimal migration, making it ideal for applications requiring long-term stability.

2. Thermal Stability and Processing Conditions

Polymer processing often involves temperatures exceeding 200°C. Not all antioxidants survive these conditions intact.

Antioxidant Thermal Decomposition Temp (°C) Suitability for High-Temp Processing
1035 ~220 Good
1010 ~230 Excellent
1076 ~200 Fair
Ethanox 330 ~250 Excellent
GP-1 ~210 Good

While Ethanox 330 leads the pack in thermal endurance, 1035 holds its own, particularly in applications where volatility matters more than peak temperature resistance.

3. Antioxidant Efficiency (Performance in Retarding Oxidation)

Efficiency is often measured via oxidative induction time (OIT) or long-term thermal aging tests.

Antioxidant OIT (minutes @ 200°C) Color Retention After Aging
1035 ~50 Good
1010 ~60 Excellent
1076 ~40 Fair
Ethanox 330 ~55 Good
GP-1 ~45 Moderate

Here, 1010 edges out others slightly, likely due to its rigid structure and efficient radical trapping. However, 1035 remains competitive, especially when balanced with its other advantages.

4. Compatibility and Processability

Some antioxidants can bloom to the surface or interfere with downstream processing.

Antioxidant Bloom Risk Compatibility with PE/PP Ease of Incorporation
1035 Very low Excellent Easy
1010 Low Excellent Slightly higher melting point complicates mixing
1076 Medium Excellent Easy
Ethanox 330 Low Good Requires careful dispersion
GP-1 Low Good Slight tendency to discolor if overheated

1035 scores well here again, especially in reducing blooming issues and maintaining clarity in transparent films.

5. Cost and Availability

Let’s face it — chemistry is cool, but budgets matter.

Antioxidant Approximate Cost ($/kg) Supplier Availability
1035 $15–20 Widely available
1010 $12–18 Abundant
1076 $10–15 Common
Ethanox 330 $20–25 Limited regional supply
GP-1 $18–22 Regional availability

While 1035 is not the cheapest option, its performance profile often justifies the premium, especially in critical applications.


Case Studies: Real-World Performance

To truly understand how these antioxidants perform, let’s look at some real-world case studies from academic and industrial sources.

Case Study 1: Polypropylene Film Stabilization

A study published in Polymer Degradation and Stability (2018) evaluated the performance of various antioxidants in PP films aged at 120°C for 1000 hours.

Antioxidant % Tensile Strength Retained Color Change (Δb*)
1035 88% +2.1
1010 92% +1.5
1076 80% +3.0
Control (no AO) 55% +6.0

While 1010 performed best in preserving tensile strength, 1035 offered a favorable balance between mechanical protection and aesthetic appeal.

Case Study 2: HDPE Pipe Aging Resistance

A 2020 report by BASF examined HDPE pipes stabilized with different antioxidants and subjected to accelerated UV and thermal aging.

Antioxidant Time to Crack Initiation (hrs) Surface Yellowing Index
1035 1500 +4.0
1010 1600 +3.5
Ethanox 330 1400 +4.5
GP-1 1300 +5.0

Again, 1035 held its own, showing robust protection against both environmental and thermal stressors.


Pros and Cons: The Bottom Line

Let’s summarize the strengths and weaknesses of Antioxidant 1035 compared to its peers.

Pros of Antioxidant 1035

  • Exceptional low volatility
  • Minimal migration
  • Good thermal stability
  • Excellent compatibility with polyolefins
  • Superior clarity in film applications
  • Balanced cost-performance ratio

Cons of Antioxidant 1035

  • Slightly lower antioxidant efficiency than 1010
  • Higher cost than simpler alternatives like 1076
  • Requires proper dispersion for full effectiveness

Choosing the Right Antioxidant: It’s All About the Application

There is no one-size-fits-all solution in polymer stabilization. The choice of antioxidant depends heavily on the application, processing conditions, and end-use requirements.

Scenario Best Choice
Transparent film requiring clarity 1035
High-temperature extrusion Ethanox 330 or 1010
Cost-sensitive commodity packaging 1076
Automotive parts needing long-term durability 1010 or GP-1
Medical devices needing low migration 1035

In essence, Antioxidant 1035 is your best friend when you need something that won’t run away from the party early — it sticks around, does its job quietly, and doesn’t mess up the vibe.


Conclusion: The Quiet Protector

In the bustling world of polymer additives, Antioxidant 1035 may not always grab headlines, but it deserves a standing ovation. Its unique combination of low volatility, excellent compatibility, and decent antioxidant power makes it an indispensable tool in the formulation chemist’s arsenal.

When compared to stalwarts like 1010, 1076, and even newer options like Ethanox 330, 1035 holds its ground — especially in niche applications where longevity and aesthetics matter most.

So next time you see a plastic bottle that looks just as good six months later as it did on day one, tip your hat to the unsung hero working behind the scenes: Primary Antioxidant 1035.


References

  1. Zweifel, H., Maier, R. D., & Schiller, M. (2014). Plastics Additives Handbook. Hanser Publishers.
  2. Gugumus, F. (2001). "Stabilization of polyolefins—XVII: Performance of commercial antioxidants in polypropylene." Polymer Degradation and Stability, 74(3), 401–410.
  3. Karlsson, K., Albertsson, A.-C., & Lindblad, M. S. (2002). "Mechanistic differences between antioxidant degradation pathways in polyethylene." Journal of Applied Polymer Science, 86(14), 3471–3481.
  4. Murthy, K. N. S., & Singh, R. P. (2003). "Effect of antioxidants on the thermal degradation of polypropylene." Journal of Vinyl and Additive Technology, 9(3), 138–144.
  5. BASF Technical Report. (2020). Long-term Stability of HDPE Pipes with Various Antioxidants. Internal Publication.
  6. Ciba Specialty Chemicals. (2005). Irganox Product Data Sheets. Basel, Switzerland.
  7. Adhesives & Sealants Industry. (2019). Choosing the Right Antioxidant for Your Polymer System. Vol. 26, Issue 2.
  8. Zhang, Y., & Wang, X. (2018). "Comparative study of hindered phenolic antioxidants in polyolefins." Polymer Degradation and Stability, 150, 88–97.
  9. Sato, H., & Yamamoto, T. (2017). "Migration behavior of antioxidants in polyethylene films." Journal of Materials Science, 52(11), 6643–6654.
  10. Evonik Industries. (2021). Ethanox 330 Technical Bulletin. Essen, Germany.

If you’re still reading this, congratulations! You’ve officially become a connoisseur of antioxidants. 🥂 Whether you’re formulating a new polymer blend or just curious about what keeps your shampoo bottle from falling apart, you now have the tools to choose wisely — and maybe even impress your lab mates with your newfound expertise.

Until next time, stay stable, my friends.

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