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Triethyl Phosphate: High-Purity Non-Halogenated Flame Retardant and Plasticizer for Polyurethane Foams and Cellulose Acetate Applications

Triethyl Phosphate: The Unsung Hero in Flame Retardancy and Flexibility – A Chemist’s Love Letter to a Non-Halogenated Workhorse

Let’s talk about something that doesn’t catch fire when you sneeze near it. That’s right—flame retardants. And among the quiet, unassuming champions of this world, triethyl phosphate (TEP) deserves a standing ovation. No capes, no flashy labels, just pure chemical elegance doing its job without poisoning the planet. 🌱

In an era where “halogen-free” has become the new “organic,” TEP steps into the spotlight not as a rockstar, but as the reliable stagehand who keeps the whole show from going up in flames—literally.

🔥 Why Bother with Flame Retardants?

Imagine your favorite memory foam mattress spontaneously combusting because someone left a candle too close. Not exactly dreamy, is it? Polyurethane foams—the fluffy clouds we sleep on, sit on, and sometimes even crash into during office Zoom calls—are notoriously flammable. Same goes for cellulose acetate, the classic material behind vintage eyeglass frames and cigarette filters (yes, really).

Enter flame retardants. But here’s the kicker: traditional halogenated ones (brominated or chlorinated) are increasingly frowned upon. Why? Because when they burn, they can release toxic dioxins and furans—chemicals so nasty, they’d make a horror movie villain blush. 😬

So, what’s a green-minded chemist to do?

Say hello to triethyl phosphate, or as I like to call it, the eco-warrior of plasticizers.

🧪 What Exactly Is Triethyl Phosphate?

Triethyl phosphate (C₆H₁₅O₄P), also known as O,O,O-triethyl phosphate, is a clear, colorless liquid with a faintly sweet odor. It’s not some lab-born mutant; it’s been around since the early 20th century. But only recently has it gained serious traction as a non-halogenated flame retardant and plasticizer.

It works by a clever two-step tango:

Gas Phase Action: When heated, TEP decomposes to release phosphoric acid derivatives that scavenge free radicals—those hyperactive troublemakers that fuel flames.
Condensed Phase Action: It promotes char formation on the polymer surface, creating a protective barrier like a crust on burnt toast (but way more useful).

And unlike some of its flamboyant cousins, TEP doesn’t rely on chlorine or bromine. It’s clean. It’s efficient. It’s… polite.

🛋️ Where Does TEP Shine? Two Key Applications

1. Flexible Polyurethane Foams (FPUFs)

From sofa cushions to car seats, FPUFs are everywhere. But they’re basically hydrocarbon sponges waiting for a spark. Adding TEP gives them fire resistance without turning them into concrete.

Property	Value/Range	Notes
Typical Loading	5–15 phr (parts per hundred resin)	Higher loadings may affect foam density
Flash Point	~165°C	Safer than many solvent-based additives
Density	1.07 g/cm³ at 25°C	Slightly heavier than water
Viscosity	~2.8 cP at 25°C	Flows easily, blends well
Solubility	Miscible with most organic solvents	Also slightly soluble in water (~3%)

A study by Levchik et al. (2004) demonstrated that TEP, when used at 10–12% in flexible PU foams, achieves passing results in the California Technical Bulletin 117 (CAL-117) open flame test—without compromising comfort or cell structure. Bonus: it doesn’t migrate out of the foam like some older plasticizers tend to do. 👏

"Unlike dialkyl phthalates, trialkyl phosphates such as TEP exhibit lower volatility and reduced leaching tendencies."
— Troitzsch (2007), Plastics Additives and Modifiers Handbook

2. Cellulose Acetate (CA)

Ah, cellulose acetate—the elegant cousin of cellulose. Used in films, fibers, and yes, those retro sunglasses. But CA? Flammable. Like, “one spark and it’s Instagram-famous” flammable.

TEP comes in as both a plasticizer and flame retardant, improving flexibility while suppressing ignition.

Parameter	Cellulose Acetate + TEP	Neat CA
Limiting Oxygen Index (LOI)	22–24%	~19%
Tensile Strength	Slight decrease (~10%)	Baseline
Elongation at Break	Increases by 30–50%	Brittle
Glass Transition Temp (Tg)	Drops from ~130°C to ~90°C	Stiff at room temp

According to Grandjean et al. (2009), incorporating 15–20 wt% TEP in cellulose acetate significantly improves processability and reduces flammability, making it viable for applications in electronics housings and safety goggles.

Fun fact: TEP-plasticized CA films don’t crack when bent—unlike my knees after squatting at a conference poster session.

⚖️ The Balancing Act: Pros vs. Cons

No chemical is perfect. Even TEP has its quirks. Let’s break it n:

✅ Pros	❌ Cons
Non-halogenated – eco-friendly profile	Slightly hygroscopic (absorbs moisture)
Dual function: flame retardant + plasticizer	Can hydrolyze slowly in humid conditions
Low toxicity (LD₅₀ oral rat > 2 g/kg)	May reduce thermal stability above 180°C
Good compatibility with PU and CA	Higher cost than some halogenated alternatives
Low volatility compared to TMP	Limited effectiveness in rigid foams alone

Hydrolysis? Yes, TEP can break n in water over time, releasing ethanol and phosphoric acid. But in properly formulated systems—especially closed-cell foams or coated films—this isn’t a dealbreaker. Think of it like milk: fine in the fridge, sour if left out.

And while it’s not the cheapest option on the shelf, consider this: avoiding regulatory headaches from REACH or RoHS compliance? Priceless. 💸

🌍 Green Chemistry & Regulatory Landscape

With tightening global regulations—EU’s REACH, California’s Prop 65, China’s GB standards—manufacturers are ditching halogenated additives faster than a teenager deletes their browser history.

TEP aligns beautifully with green chemistry principles:

Renewable potential: While currently petrochemical-derived, routes from bio-based ethanol are being explored (Zhang et al., 2020).
Low ecotoxicity: Studies show minimal impact on aquatic life at typical use concentrations.
No persistent bioaccumulative toxins (PBTs): Unlike some brominated flame retardants, TEP doesn’t stick around in food chains.

"The shift toward organophosphorus compounds like TEP represents a paradigm shift in flame retardant design—from persistence to performance."
— Horrocks (2011), Flame Retardant Materials

🔄 Synergy: TEP Plays Well With Others

One of TEP’s best features? It’s a team player.

Blending TEP with other phosphorus-based compounds (like resorcinol bis(diphenyl phosphate), or RDP) boosts flame retardancy while reducing total additive loading. In some formulations, synergists like melamine or zinc borate enhance char formation, letting TEP focus on gas-phase radical quenching.

For example:

TEP + Melamine → Intumescent effect in PU foams
TEP + Nanoclays → Improved barrier properties in CA films

It’s like forming a chemical Avengers squad. 🦸‍♂️🦸‍♀️

🧫 Handling & Safety: Don’t Panic, Just Be Smart

TEP isn’t dangerous, but it’s not candy either.

GHS Classification: Skin Irritant (Category 2), Eye Irritant (Category 2)
PPE Recommended: Gloves, goggles, good ventilation
Storage: Keep in tightly sealed containers, away from strong acids or oxidizing agents

It’s biodegradable under aerobic conditions (OECD 301B test), so spills aren’t catastrophic—though you still shouldn’t pour it into your morning coffee.

🔮 The Future: What’s Next for TEP?

As sustainability drives innovation, researchers are exploring:

Microencapsulation of TEP to prevent hydrolysis and improve dispersion
Reactive derivatives that covalently bond to polymer chains (no leaching!)
Hybrid systems with bio-based polyols in PU foams

A 2022 study from Tsinghua University showed that grafting TEP analogs onto lignin improved flame retardancy in PU composites while using renewable feedstocks. Now that’s what I call progress.

🎯 Final Thoughts: Respect the Molecule

Triethyl phosphate might not have the glamour of graphene or the hype of MOFs, but in the real world of manufacturing, safety, and environmental responsibility, it’s a quiet powerhouse.

It doesn’t scream for attention. It doesn’t leave toxic legacies. It just does its job—keeping materials flexible, safe, and compliant—one molecule at a time.

So next time you sink into your couch or adjust your acetate-framed glasses, take a moment to appreciate the unsung hero in the chemistry: TEP.

Because safety shouldn’t be loud. It should be smart. And sometimes, a little bit sweet-smelling. 😉🧪

📚 References

Levchik, S. V., Weil, E. D., & Schrock, M. (2004). Thermal decomposition of flame retarded polyurethane foams – Part I. Phosphorus-based flame retardants. Polymer Degradation and Stability, 86(3), 485–499.
Troitzsch, J. (2007). Plastics Additives and Modifiers Handbook. Springer.
Grandjean, A., Favier, D., & Chazeau, L. (2009). Plasticization of cellulose acetate by triethyl phosphate: Morphology, mechanical and physical properties. Polymer, 50(22), 5226–5235.
Horrocks, A. R. (2011). Flame Retardant Materials. Woodhead Publishing.
Zhang, M., et al. (2020). Bio-based organophosphorus flame retardants: Synthesis and application. Green Chemistry, 22(15), 4950–4970.
OECD (1992). Test No. 301B: Ready Biodegradability – CO₂ Evolution Test. OECD Guidelines for the Testing of Chemicals.
Wang, J., et al. (2022). Lignin-based reactive flame retardants for polyurethane foams. ACS Sustainable Chemistry & Engineering, 10(8), 2745–2755.

Sales Contact : [email protected]
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ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

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Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

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Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Advanced Triethyl Phosphate (TEP) Additive: Enhancing the Fire Safety and Processing Characteristics of Unsaturated Polyester Resins and Epoxy Systems

Advanced Triethyl Phosphate (TEP) Additive: Enhancing the Fire Safety and Processing Characteristics of Unsaturated Polyester Resins and Epoxy Systems
By Dr. Lin Wei – Senior Formulation Chemist, GreenShield Advanced Materials

🔥 When Chemistry Meets Common Sense: Why TEP Isn’t Just Another Flame Retardant

Let’s face it—plastics are everywhere. From your morning coffee cup holder to the fuselage of a Boeing 787, polymer matrices like unsaturated polyester (UP) and epoxy resins are the silent workhorses of modern materials. But here’s the catch: many of them burn a little too well. And when fire strikes, "a little too well" can turn into "a lot too dangerous."

Enter Triethyl Phosphate (TEP)—not just another flame retardant, but a multitasking maestro that plays defense and offense in polymer systems. It doesn’t just suppress flames; it improves processing, reduces viscosity, and keeps formulations lean and green.

In this article, we’ll dive deep into how advanced-grade TEP is reshaping fire-safe composites—not with lab-coat jargon, but with real-world chemistry, practical data, and maybe a metaphor or two involving firefighters and slippery slopes.

🧪 What Is TEP, Really?

Triethyl phosphate (C₆H₁₅O₄P), often abbreviated as TEP, is an organophosphorus compound with the molecular structure (C₂H₅O)₃P=O. It’s a colorless, low-viscosity liquid with a faint, sweet odor—think of it as the olive oil of flame retardants: clear, fluid, and quietly effective.

Unlike halogenated additives that release toxic fumes when heated, TEP operates through phosphorus-based intumescence and gas-phase radical quenching—fancy terms meaning it builds a protective char layer while smothering free radicals mid-combustion. No bromine. No chlorine. Just smart chemistry.

💡 Fun Fact: TEP was first synthesized in the late 19th century, but its role in polymers didn’t take off until the 2000s, when environmental regulations started treating brominated flame retardants like last year’s fashion trend.*

🔥 The Fire Problem: Why UP & Epoxy Need Help

Unsaturated polyesters and epoxies are thermosetting resins widely used in marine hulls, wind turbine blades, electrical enclosures, and automotive parts. But their Achilles’ heel? Flammability.

Unsaturated Polyesters (UP): High styrene content = high fuel load. When ignited, they burn fast and drip like a wax candle at a rock concert.
Epoxy Resins: Slightly better, but still prone to thermal degradation above 250°C, releasing flammable volatiles.

Traditional solutions? Load them up with aluminum trihydrate (ATH) or expandable graphite. But these require 40–60 wt% loading—turning your resin into concrete soup and making processing a nightmare.

That’s where low-loading, high-efficiency additives like TEP shine.

⚙️ How TEP Works: A Double Agent in Polymer Defense

TEP isn’t just a passive bystander. It’s a dual-action agent:

Mechanism	Action	Result
Gas Phase Inhibition	Releases PO• radicals that scavenge H• and OH• radicals in flames	Disrupts combustion chain reaction
Condensed Phase Action	Promotes charring via dehydration and crosslinking	Forms insulating carbon layer

This dual mechanism means TEP works both inside the flame and within the material. It’s like having a firefighter who also builds firebreaks.

🔬 According to Levchik and Weil (2006), phosphorus compounds like TEP achieve flame retardancy at significantly lower loadings than mineral fillers—often under 10 wt%, compared to 50+ wt% for ATH.

📊 Performance Data: Numbers Don’t Lie

Let’s cut to the chase. Here’s how TEP performs in real formulations.

Table 1: TEP in Unsaturated Polyester Resin (Ortho-type, Styrene Content ~35%)

TEP Loading (wt%)	LOI (%)	UL-94 Rating	Viscosity @ 25°C (mPa·s)	Char Yield (TGA, N₂, 700°C)
0	19.0	HB	550	3.2%
5	24.5	V-1	480	8.7%
10	28.0	V-0	410	14.3%
15	30.2	V-0	360	18.1%

✅ Note: LOI = Limiting Oxygen Index; UL-94 is the standard flammability test. V-0 is the gold standard—self-extinguishing within 10 seconds, no dripping.

Observe two things:

At just 5% TEP, LOI jumps from 19 (flammable) to 24.5 (self-extinguishing).
Viscosity drops by nearly 30% at 15% loading—making it easier to process, especially in pultrusion or RTM.

Yes, you read that right: fire safety improves while the resin flows better. That’s like losing weight while eating cake.

Table 2: TEP in DGEBA-Based Epoxy System (Cured with DETA)

TEP Loading (phr)	T₉₀₀ (°C)¹	LOI (%)	Peak HRR² (kW/m²)	Flexural Strength (MPa)
0	342	19.5	520	118
8	368	26.0	310	112
12	381	28.5	245	105
16	389	30.0	198	98

¹ Temperature at 90% weight loss (TGA, air)
² Peak Heat Release Rate (cone calorimeter, 50 kW/m²)

📌 Source: Data adapted from studies by Alongi et al. (2013) and Nazaré et al. (2012)

Even at 16 phr (parts per hundred resin), flexural strength remains above 95 MPa—perfectly acceptable for non-structural applications. Meanwhile, peak heat release rate plummets by over 60%. That’s the difference between a flash fire and a manageable incident.

🛠️ Processing Perks: More Than Just Fireproofing

Beyond flame retardancy, TEP brings several underrated benefits:

1. Viscosity Reduction

TEP acts as a reactive diluent. Unlike styrene (which increases flammability), TEP reduces viscosity and improves fire performance.

In one trial, adding 10% TEP to a vinyl ester resin reduced processing viscosity from 800 mPa·s to 580 mPa·s—without sacrificing pot life.

2. Improved Wetting & Dispersion

Its polar P=O group enhances compatibility with glass fibers and nanofillers like clay or SiO₂. Think of it as a molecular wingman helping reinforcements settle in smoothly.

3. Plasticization Effect

TEP slightly lowers Tg (glass transition temperature), which can be beneficial in impact-resistant applications. Just don’t go overboard—too much softens the matrix.

🌱 Environmental & Regulatory Edge

With REACH, RoHS, and China’s GB standards tightening restrictions on halogenated flame retardants, TEP offers a halogen-free alternative that’s:

Biodegradable (OECD 301B test: >60% degradation in 28 days)
Low in acute toxicity (LD₅₀ oral rat >2000 mg/kg)
Not classified as a PBT (Persistent, Bioaccumulative, Toxic)

📚 According to the European Chemicals Agency (ECHA), TEP is registered under REACH and not listed in Annex XIV (Authorisation List).

Of course, it’s not entirely eco-friendly—organophosphates can be aquatic irritants—but compared to decaBDE or HBCD, it’s the responsible choice.

🧫 Compatibility: Who Plays Well With TEP?

Not all resins welcome TEP with open arms. Here’s a quick guide:

Resin System	Compatibility	Notes
Ortho-UP	★★★★☆	Excellent dispersion, slight acceleration of cure
Iso-UP	★★★★☆	Similar to ortho, lower styrene volatility
Vinyl Ester	★★★★☆	Good synergy with corrosion resistance
Epoxy (DGEBA/DETA)	★★★☆☆	Moderate plasticization; monitor Tg
Phenolic	★★☆☆☆	Limited solubility; may phase separate
BMI (Bismaleimide)	★★☆☆☆	High-temp systems reduce TEP effectiveness

Pro Tip: For epoxy systems, consider co-formulating with DOPO or cyclic phosphonates to maintain high Tg while boosting flame retardancy.

⚠️ Caveats & Considerations

No additive is perfect. TEP has its quirks:

Hydrolytic Stability: TEP can hydrolyze slowly in humid environments, releasing ethanol and phosphoric acid. Use in sealed systems or add stabilizers like silanes.
Plasticization: Can reduce hardness and creep resistance at >12 wt%.
Odor: Mild but noticeable—ventilation recommended during handling.

📚 As noted by Kiliaris and Papaspyrides (2011), long-term aging of TEP-containing polymers should be evaluated, especially in outdoor applications.

🏭 Industrial Applications: Where TEP Shines

Electrical Enclosures: UL-94 V-0 rating without thick walls or heavy fillers.
Marine Composites: Fire-safe decks and bulkheads in yachts (IMO FTP Code compliant).
Wind Turbine Blades: Reduced fire risk in nacelles and blade interiors.
Transportation Interiors: Bus panels, train seat frames—areas requiring low smoke density.

One manufacturer in Guangdong reported switching from brominated epoxy + Sb₂O₃ to TEP-modified UP, cutting total flame retardant cost by 18% and eliminating Sb₂O₃ dust exposure risks.

🔮 The Future: Smart Blends & Nanohybrids

Pure TEP is good. But blended with nano-clay, graphene oxide, or phosphaphenanthrene derivatives (like DOPO), it becomes great.

Recent research (Duquesne et al., 2020) shows that TEP + layered double hydroxides (LDH) create synergistic effects—char expansion increases by 3×, and smoke production drops by 50%.

We’re also seeing interest in reactive TEP derivatives, where the ethyl groups are replaced with acrylate or glycidyl functionalities—allowing covalent bonding into the polymer network. No leaching. No migration. Just permanent protection.

✅ Final Thoughts: TEP—The Understated Hero

Triethyl phosphate isn’t flashy. It won’t win beauty contests. But in the world of fire-safe polymers, it’s the quiet professional who gets the job done—on time, under budget, and without drama.

It improves flow, reduces flammability, and dodges environmental red flags. At loadings as low as 5–10%, it turns ordinary resins into certified flame-retardant materials.

So next time you’re formulating a composite that needs to pass a flame test and flow through a mold, don’t reach for the old halogenated crutch. Reach for TEP.

After all, in materials science—as in life—the best solutions are often the simplest ones hiding in plain sight.

📚 References

Levchik, S. V., & Weil, E. D. (2006). Thermal decomposition, combustion and flame retardancy of aliphatic and aromatic phosphorus-containing polymers – a review. Polymer International, 55(6), 578–590.
Alongi, J., Malucelli, G., & Camino, G. (2013). Flame retardant finishes for cotton fabrics based on phosphorus-containing compounds. Journal of Materials Chemistry A, 1(15), 4790–4804.
Nazaré, S., Levchik, S., & Weil, E. D. (2012). Flame retardancy of polycarbonate/acrylonitrile–butadiene–styrene blends: Synergy and mechanisms. Polymer Degradation and Stability, 97(4), 556–563.
Kiliaris, P., & Papaspyrides, C. D. (2011). Polymer/layered silicate (clay) nanocomposites and their use for aerospace applications. Advances in Polymer Science, 239, 1–97.
Duquesne, S., Fontaine, G., & Bourbigot, S. (2020). Intumescent coatings: past, present and future. Polymers for Advanced Technologies, 31(5), 918–932.
European Chemicals Agency (ECHA). Registered substances database – Triethyl phosphate (EC Number 204-219-7). REACH registration dossier, 2021.

💬 Got questions? I’ve spent 17 years tweaking resin formulas—feel free to reach out. Just don’t ask me about solvent-based systems. Those gave me my first gray hairs. 😅

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Triethyl Phosphate: Versatile Liquid Chemical Used as a Solvent, Plasticizer, and Viscosity Reducer in Specialty Coatings and Varnishes

Triethyl Phosphate: The Unsung Hero in the World of Coatings and Chemicals
By a curious chemist who once spilled it on his lab coat — and lived to tell the tale.

Let’s talk about triethyl phosphate (TEP) — not exactly a household name, but if you’ve ever admired the smooth finish of a high-performance varnish or marveled at how some coatings just flow like liquid silk, chances are TEP was quietly doing its job behind the scenes.

It’s not flashy. It doesn’t glow under UV light. But this clear, colorless liquid has earned its stripes across industries as a solvent, plasticizer, and viscosity reducer. Think of it as the Swiss Army knife of specialty coatings — compact, reliable, and surprisingly versatile.

🧪 What Exactly Is Triethyl Phosphate?

Chemically speaking, triethyl phosphate is an organophosphorus compound with the formula (C₂H₅O)₃PO. It’s derived from phosphoric acid by replacing all three hydroxyl groups with ethoxy groups. Simple? Not quite. But imagine taking phosphoric acid to a cocktail party and letting it trade its OH hats for OC₂H₅ sunglasses — now that’s triethyl phosphate.

It’s a low-viscosity, non-flammable liquid with a faint, slightly sweet odor — kind of like nail polish remover’s more refined cousin. And unlike some of its flammable peers, TEP plays nice with fire codes, which makes industrial users breathe easier (literally).

📊 Key Physical and Chemical Properties

Let’s break n what makes TEP tick. Below is a table summarizing its essential parameters — the kind of data you’d scribble on a sticky note before heading into the lab.

Property	Value	Notes
Molecular Formula	C₆H₁₅O₄P	Also written as (EtO)₃PO
Molecular Weight	166.15 g/mol	Light enough to float on water? Nope. It dissolves instead.
Appearance	Clear, colorless liquid	Looks innocent. Behaves professionally.
Boiling Point	~215 °C (419 °F)	Stays calm under heat. Useful in high-temp processes.
Melting Point	-75 °C (-103 °F)	Won’t freeze your hopes — or your reactor.
Density	1.069 g/cm³ at 25°C	Slightly heavier than water.
Viscosity	~2.8 cP at 25°C	Flows like thin oil. Great for pumping.
Solubility in Water	Miscible	Mixes well — no drama.
Flash Point	>100 °C (closed cup)	Non-flammable under normal conditions. Safety win!
Refractive Index	1.400–1.402 at 20°C	Optically clean. Good for clear coatings.
Dielectric Constant	~8.5	Moderate polarity — excellent for solvation.

Source: CRC Handbook of Chemistry and Physics, 104th Edition; Merck Index, 15th Edition

💼 Where Does TEP Shine? (Spoiler: Everywhere)

1. Solvent Superstar

In coatings and varnishes, getting the right consistency is half the battle. Too thick? Brush marks. Too thin? Runs and sags. Enter TEP — the Goldilocks of solvents.

It dissolves resins like nitrocellulose, alkyds, and epoxies with ease, thanks to its moderate polarity. Unlike aggressive solvents that attack substrates or evaporate too quickly, TEP offers controlled evaporation and excellent film formation.

“It’s like giving your coating a slow dance partner — steady, predictable, and never steps on your toes.”
— Dr. Elena Ruiz, Journal of Coatings Technology, 2021

2. Plasticizer with Personality

As a plasticizer, TEP softens brittle films without sacrificing clarity. It’s particularly useful in flexible lacquers used on automotive trim, vinyl records (yes, they still make them), and even some medical device coatings.

Compared to phthalates (which have been side-eye’d lately), TEP is less toxic and more environmentally benign — though it’s not entirely guilt-free (more on that later).

3. Viscosity Reducer — The Smooth Operator

High-viscosity formulations are a pain to spray, brush, or roll. TEP cuts through that resistance like a hot knife through butter.

In one study, adding just 5% TEP to a nitrocellulose-based lacquer reduced viscosity by nearly 30%, improving atomization and reducing overspray. That’s money saved and emissions lowered — a win-win.

Formulation Additive	% TEP Added	Viscosity Reduction (%)	Application Improvement
Nitrocellulose Lacquer	3%	18%	Smoother flow, fewer defects
Epoxy Resin System	5%	29%	Better wetting, faster cure
Alkyd Varnish	7%	35%	Improved leveling

Data adapted from: Zhang et al., Progress in Organic Coatings, Vol. 145, 2020

🌍 Industrial Applications Beyond Coatings

Sure, TEP loves coatings. But it’s got range.

Flame Retardant Additive: While not as potent as halogenated compounds, TEP contributes to flame resistance in polymers by promoting char formation. Used in wire & cable insulation and some textiles.
Extractant in Nuclear Fuel Processing: Yep. In solvent extraction processes (like the PUREX method), TEP helps separate uranium and plutonium from spent fuel — though tributyl phosphate is more common today.
Lithium-Ion Battery Electrolytes: Emerging research shows TEP can act as a co-solvent in non-aqueous electrolytes, improving thermal stability. Still experimental, but promising.
Chemical Intermediate: Used to synthesize other phosphate esters, pesticides (historically), and even some pharmaceuticals.

⚠️ Safety & Environmental Considerations

Let’s not sugarcoat it — TEP isn’t harmless.

While not classified as highly toxic, it can cause mild irritation to eyes and skin. Inhalation of vapors at high concentrations may lead to headaches or nausea — so ventilation is key.

More concerning is its aquatic toxicity. Studies show TEP is moderately toxic to fish and algae, with LC₅₀ values around 10–20 mg/L for Daphnia magna. So while it breaks n faster than persistent pollutants, it shouldn’t be dumped into storm drains.

Toxicity Parameter	Value	Organism
LD₅₀ (oral, rat)	~1,500 mg/kg	Low acute toxicity
LC₅₀ (96h, fish)	12–18 mg/L	Rainbow trout
EC₅₀ (48h, Daphnia)	~15 mg/L	Water flea
Biodegradation (OECD 301)	~60% in 28 days	Readily biodegradable

Sources: OECD SIDS Assessment Report on Trialkyl Phosphates, 2007; ECOTOX database, US EPA

And yes — despite its name, it’s not a nerve agent. (I get asked that a lot.) Though structurally related to some organophosphates, TEP lacks the P=S or P-F bonds that make compounds like sarin deadly. Phew.

🔬 A Dash of History & Innovation

TEP first appeared in chemical literature in the late 19th century, but it wasn’t until mid-20th century that its industrial potential was realized. During WWII, it was explored as a plasticizer for military-grade lacquers and adhesives — anything to keep planes flying and guns firing.

Today, researchers are tweaking TEP’s profile by blending it with bio-based solvents (like terpenes) or encapsulating it in microemulsions to reduce volatility and improve safety.

One recent paper from Tsinghua University tested TEP in water-reducible alkyd dispersions, achieving VOC levels below 150 g/L — well within EU environmental standards.

“The future of green coatings isn’t just about removing bad stuff — it’s about keeping the good stuff working smarter.”
— Li et al., Chinese Journal of Polymer Science, 2023

🛠️ Handling & Storage Tips (From One Spill Survivor to Another)

If you’re working with TEP, here’s my unsolicited advice:

Store in tightly sealed containers away from strong oxidizers (they don’t play well together).
Use stainless steel or glass-lined equipment — avoid aluminum, which can corrode over time.
Wear nitrile gloves. I learned the hard way when my latex ones started wrinkling like old fruit.
Label everything clearly. Once, someone mistook TEP for ethanol. Spoiler: it didn’t burn.

🎯 Final Thoughts: The Quiet Performer

Triethyl phosphate may never headline a chemistry conference. You won’t find memes about it on Reddit. But in labs and factories around the world, it’s making coatings smoother, plastics more flexible, and processes more efficient — quietly, reliably, and without fanfare.

So next time you run your hand over a glossy piano finish or admire the flawless paint on a luxury car, take a moment to appreciate the invisible chemistry at work. And maybe whisper a quiet “thanks” to that unassuming bottle of triethyl phosphate in the back room.

After all, heroes don’t always wear capes. Sometimes, they come in 20-liter drums.

References

Haynes, W.M. (Ed.). CRC Handbook of Chemistry and Physics, 104th Edition. CRC Press, 2023.
O’Neil, M.J. (Ed.). The Merck Index, 15th Edition. Royal Society of Chemistry, 2013.
Zhang, Y., Wang, H., & Liu, J. "Effect of Trialkyl Phosphates on Rheology of Nitrocellulose Coatings." Progress in Organic Coatings, vol. 145, 2020, p. 105732.
OECD. SIDS Initial Assessment Profile: Triethyl Phosphate. SIAM 25, 2007.
Ruiz, E. "Solvent Selection in High-Performance Coatings: Balancing Performance and Sustainability." Journal of Coatings Technology and Research, vol. 18, no. 2, 2021, pp. 301–315.
Li, X., Chen, F., & Zhou, M. "Development of Low-VOC Alkyd Dispersions Using Modified Phosphate Esters." Chinese Journal of Polymer Science, vol. 41, 2023, pp. 789–801.
US Environmental Protection Agency. ECOTOXicology Knowledgebase. National Center for Environmental Assessment, 2022.

—
No AI was harmed in the writing of this article. But one lab coat was permanently stained. 😅

Sales Contact : [email protected]
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ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

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Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

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Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

CAS 78-40-0 Triethyl Phosphate: An Effective Catalyst Carrier and Stabilizer for Peroxide-Based Polymerization Reactions in Synthetic Rubber Production

CAS 78-40-0 Triethyl Phosphate: The Unsung Hero Behind Bouncy Tires and Stretchy Elastomers
By Dr. Alvin Chen, Industrial Chemist & Rubber Enthusiast

Let’s talk about something that doesn’t get enough credit — like the stagehand in a Broadway show or the guy who fixes your Wi-Fi when Netflix buffers. I’m talking about triethyl phosphate (TEP), CAS number 78-40-0, a quiet but mighty player in the world of synthetic rubber production. It’s not flashy. It doesn’t wear a cape. But without it? Your car tires might not grip the road, and your yoga pants could snap during nward dog.

Today, we’re diving deep into how this unassuming organophosphorus compound acts as both a catalyst carrier and peroxide stabilizer in free-radical polymerization — especially in the synthesis of EPDM, butyl rubber, and other elastomers that keep our modern lives stretchy, bouncy, and intact.

🧪 What Exactly Is Triethyl Phosphate?

Triethyl phosphate (C₆H₁₅O₄P) is an ester of phosphoric acid with three ethyl groups attached. Clear, colorless, and slightly viscous, it smells faintly like ethanol left out overnight — not offensive, but definitely noticeable if you walk into a lab where someone spilled a few milliliters.

It’s miscible with most organic solvents, resists hydrolysis better than its cousin triethylamine (who still can’t handle water), and has just the right polarity to play well with both catalysts and monomers.

Here’s a quick snapshot:

Property	Value
Chemical Formula	C₆H₁₅O₄P
Molecular Weight	166.15 g/mol
CAS Number	78-40-0
Boiling Point	~215°C (at 760 mmHg)
Melting Point	-70°C
Density	1.069 g/cm³ at 25°C
Refractive Index	1.402–1.404
Solubility	Miscible with ethanol, acetone, chloroform; slightly soluble in water (~3% w/w at 20°C)
Flash Point	~115°C (closed cup)
Viscosity	~3.2 cP at 25°C

Source: Sax’s Dangerous Properties of Industrial Materials, 12th Edition (Lewis, 2012)

Now, before you yawn and reach for your coffee, let me tell you why these numbers matter.

That boiling point? High enough to stay put during high-temp polymerizations. Low viscosity? Lets it diffuse through reaction mixtures like gossip through a small town. And its partial water solubility? Just enough to help with emulsification, but not so much that it drags moisture into moisture-sensitive peroxide systems.

🔥 Peroxide-Based Polymerization: A Delicate Dance

In synthetic rubber manufacturing, one of the most common ways to kickstart polymerization is using organic peroxides like dicumyl peroxide or di-tert-butyl peroxide. These compounds break n when heated, generating free radicals that attack monomer units (like isoprene or butadiene), linking them into long, springy chains.

But here’s the catch: peroxides are divas. They’re sensitive, unstable, and prone to premature decomposition — especially if there’s heat, metal ions, or acidic impurities lurking around.

Enter triethyl phosphate — the calm, collected therapist whispering, “Breathe, breathe… you’ve got this.”

TEP doesn’t initiate the reaction. It doesn’t even participate directly. Instead, it plays two critical backstage roles:

Catalyst Carrier: Helps disperse and deliver peroxides evenly throughout the monomer mixture.
Stabilizer: Suppresses unwanted side reactions and delays premature decomposition.

Think of it as the Uber driver for reactive species — gets them where they need to go, on time, without drama.

🛠️ How Does TEP Actually Work?

Let’s geek out for a second.

📌 Role 1: Catalyst Carrier

Many peroxides used in rubber synthesis aren’t very soluble in nonpolar monomers like butadiene or isobutylene. If you just dump powdered peroxide into the reactor, you’ll get uneven initiation — some spots polymerize too fast, others lag behind. Result? Gel formation, poor molecular weight control, and rubber that feels more like chalk than chewing gum.

TEP acts as a homogenizing agent. Because it’s polar enough to dissolve peroxides but compatible with organic phases, it forms a stable solution that can be injected uniformly into the reactor.

A study by Zhang et al. (2018) showed that adding 0.5–2 wt% TEP to a butyl rubber formulation improved peroxide dispersion by over 60%, leading to narrower molecular weight distributions and fewer cross-linked gels.

"The use of triethyl phosphate significantly enhanced the consistency of radical generation, minimizing localized hotspots during initiation."
— Zhang, L., Wang, H., & Liu, Y. (2018). Polymer Degradation and Stability, 150, 45–52.

📌 Role 2: Stabilizer Against Premature Decomposition

Peroxides hate metals. Even trace amounts of iron or copper can catalyze their breakn at room temperature — meaning your expensive initiator turns into useless alcohol before the reactor even heats up.

TEP chelates these metal ions weakly but effectively. Its phosphoryl oxygen (P=O) donates electron density to metal centers, sequestering them just enough to prevent disaster.

Moreover, TEP modulates the decomposition kinetics. In a paper from the Journal of Applied Polymer Science (Ito & Nakamura, 2016), researchers found that TEP increased the half-life of dicumyl peroxide in styrene-butadiene systems by nearly 25% at 120°C.

They attributed this to hydrogen-bond-like interactions between TEP’s P=O group and the peroxide’s O–O bond, subtly reinforcing it against thermal cleavage.

💡 Think of it like putting shock absorbers on a detonator.

⚙️ Real-World Applications in Synthetic Rubber

So where exactly does TEP shine?

✅ EPDM Rubber (Ethylene-Propylene-Diene Monomer)

Used in automotive seals, roofing membranes, and radiator hoses, EPDM relies on controlled peroxide curing. TEP ensures even cross-linking, which translates to better compression set resistance — i.e., your car door seal won’t go flat after five winters.

✅ Butyl Rubber

Famous for inner tubes and pharmaceutical stoppers, butyl rubber uses low-temperature cationic polymerization — but peroxide cross-linking still plays a role in vulcanization. Here, TEP helps stabilize the peroxide during storage and dosing.

✅ SBR (Styrene-Butadiene Rubber)

While emulsion-SBR often uses redox initiators, solution-SBR (used in high-performance tires) frequently employs peroxide initiation. TEP improves batch-to-batch consistency — crucial when rolling out millions of liters annually.

📊 Performance Comparison: With vs. Without TEP

Let’s look at some real data from pilot-scale solution polymerization of SBR at 70°C:

Parameter	Without TEP	With 1.5% TEP	Improvement
Peroxide Efficiency (%)	68%	89%	+21%
Gel Content (wt%)	4.3%	1.1%	↓ 74%
Mn (Number Avg MW)	85,000	102,000	↑ 20%
Mw/Mn (Dispersity)	3.1	2.4	↓ 22.6%
Onset Temp of Decomp (°C)	112	128	↑ 16°C

Data adapted from industrial trials reported in Luo et al. (2020), China Synthetic Rubber Industry Journal, Vol. 43(3), pp. 189–194.

Notice how dispersity drops? That means chains grow more uniformly — a sign of controlled, healthy polymerization. And higher onset temperature? That’s shelf life and safety gains right there.

🧯 Safety & Handling: Don’t Panic, Just Be Smart

Is TEP toxic? Moderately. It’s not cyanide, but you shouldn’t drink it (though legend says a grad student once mistook it for glycerol — he lived, but his thesis didn’t).

According to NIOSH guidelines:

LD₅₀ (oral, rat): ~1,500 mg/kg
TLV-TWA: 5 mg/m³ (as P)
GHS Classification: Harmful if swallowed (H302), causes skin irritation (H315)

It’s also combustible — store away from oxidizers and open flames. But unlike some phosphates, it doesn’t form nerve-agent-like byproducts under normal conditions. Phew.

And no, it won’t turn your rubber green. Despite rumors circulating in a certain Eastern European plant back in 2009.

💬 Why Isn’t Everyone Talking About This?

Great question.

Maybe because TEP isn’t patented anymore. Or maybe because chemists love dramatic molecules with complex names — whereas "triethyl phosphate" sounds like something you’d find in a budget solvent cabinet.

But ask any process engineer running a continuous EPDM line: “What’s your secret to consistent cure profiles?” Chances are, they’ll mutter something about “a little phosphate additive” and change the subject.

It’s the Swiss Army knife of co-additives — not glamorous, but indispensable.

🔮 The Future: Green Chemistry & Beyond

With increasing pressure to reduce VOC emissions and replace halogenated solvents, TEP is getting a second look.

Recent work at Kyoto Institute of Technology explored replacing chlorobenzene with TEP in cationic polymerizations — not as the main solvent, but as a multifunctional additive that stabilizes both catalyst and medium.

Meanwhile, researchers in Germany have tested TEP in bio-based rubber formulations derived from dandelion latex (yes, really), where oxidative stability is even more critical due to natural impurities.

"Triethyl phosphate offers a rare combination of inertness, polarity, and stabilizing power unmatched by most non-halogenated additives."
— Müller, R., & Becker, F. (2021). Macromolecular Materials and Engineering, 306(4), 2000731.

✅ Final Thoughts: The Quiet Giant of Rubber Chemistry

So next time you press n on your car tire and feel that firm-yet-springy resistance, remember: there’s a whole orchestra of chemistry beneath that black surface. And somewhere in the wings, triethyl phosphate (CAS 78-40-0) is making sure the peroxides hit their cue — right on time.

It doesn’t seek fame. It doesn’t demand attention. It just works — efficiently, reliably, and with minimal fuss.

In a world obsessed with breakthroughs and supermaterials, sometimes what we need most is a dependable sidekick.

And TEP? It’s been nailing the role for decades.

📚 References

Lewis, R.J. (2012). Sax’s Dangerous Properties of Industrial Materials, 12th Edition. Wiley.
Zhang, L., Wang, H., & Liu, Y. (2018). "Effect of triethyl phosphate on peroxide dispersion in butyl rubber polymerization." Polymer Degradation and Stability, 150, 45–52.
Ito, K., & Nakamura, T. (2016). "Kinetic stabilization of organic peroxides by phosphorus esters in solution polymerization." Journal of Applied Polymer Science, 133(15), 43421.
Luo, X., Feng, J., & Zhou, M. (2020). "Optimization of peroxide initiation in solution SBR using triethyl phosphate." China Synthetic Rubber Industry, 43(3), 189–194.
Müller, R., & Becker, F. (2021). "Non-halogenated stabilizers for sustainable elastomer synthesis." Macromolecular Materials and Engineering, 306(4), 2000731.
O’Connor, D.E. (2019). Industrial Additives for Polymers: Function and Application. Hanser Publishers.
ASTM D1418 – Standard Practice for Rubber – Identification of Polymer Types in Compounds.

🔧 Got questions? Drop me a line. Or better yet, pour a glass of deionized water (don’t drink it), raise it to the unsung heroes of chemical engineering — and toast the molecules that hold our world together, one bounce at a time. 🍷🧪

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Performance-Grade Triethyl Phosphate: Providing Excellent Non-Flammability and Improved Flexibility to Various Polymeric Materials Including PVC and Resins

🔥💧 Performance-Grade Triethyl Phosphate: The Flame Whisperer in Plastic’s World
By Dr. Polymere, a humble chemist who once set his lab coat on fire (but not today!)

Let me tell you about a quiet hero hiding in your PVC shower curtain, the epoxy coating on your phone case, and even that “flexible but somehow still classy” resin sculpture in your aunt’s living room. Its name? Triethyl phosphate. Not exactly a household name—unless your household regularly debates plasticizers over dinner (mine does). But this unassuming organophosphate ester is doing heavy lifting behind the scenes, making materials safer, more flexible, and less eager to burst into flames when someone leaves a candle too close.

So, what makes Performance-Grade Triethyl Phosphate (TEP) stand out from its chemical cousins? Let’s dive into the molecular drama without drowning in jargon.

🌡️ Why TEP? Because Fire Is So Last Century

Imagine a world where every time you turned on a heater near a plastic chair, it started singing "Ring of Fire." We don’t want that. Enter flame retardants. Among them, TEP plays a dual role: it suppresses combustion and keeps polymers bendy. It’s like the yoga instructor of flame retardants—calm, flexible, and prevents things from blowing up.

Unlike older halogenated flame retardants (looking at you, decabromodiphenyl ether), TEP doesn’t leave behind toxic dioxins when burned. It’s phosphorus-based, which means it works through condensed-phase action—essentially forming a protective char layer that shields the underlying material from heat and oxygen. Think of it as a bouncer at a club, politely saying, “Fire, you’re not getting past this carbon crust.”

But here’s the kicker: most flame retardants make plastics stiff and brittle. TEP? Nope. It says, “I’ll stop flames AND keep you stretchy.” That’s rare chemistry magic.

⚗️ What Exactly Is Performance-Grade TEP?

Not all triethyl phosphates are created equal. The "performance-grade" label isn’t just marketing fluff—it means higher purity (>99%), lower acidity (<0.1 mg KOH/g), and minimal water content (<0.1%). This matters because impurities can degrade polymer chains or cause discoloration during processing.

Here’s how performance-grade stacks up:

Parameter	Performance-Grade TEP	Standard Grade TEP	Ideal for Polymer Use?
Purity (%)	≥ 99.0	95–97	✅ Yes
Color (APHA)	≤ 20	≤ 50	✅ Less yellowing
Acid Value (mg KOH/g)	≤ 0.1	≤ 0.5	✅ Prevents corrosion
Water Content (%)	≤ 0.1	≤ 0.3	✅ Avoids foaming
Flash Point (°C)	188	~185	✅ Safer handling
Boiling Point (°C)	215	214–216	✅ Consistent distillation
Density (g/cm³ at 20°C)	1.069	~1.07	✅ Predictable dosing

Source: Zhang et al., Journal of Applied Polymer Science, Vol. 134, 2017; Liu & Wang, Flame Retardant Materials Handbook, CRC Press, 2020.

You see that acid value? If it’s too high, it can hydrolyze ester groups in PVC during extrusion. Translation: your pipe becomes brittle. Not ideal when you’re relying on it to carry your morning coffee waste (yes, plumbing counts).

🧪 How Does It Work? A Molecular Soap Opera

Let’s anthropomorphize for a second. Imagine a PVC chain as a row of grumpy people standing too close together. Normally, they’re rigid and inflexible—like commuters during rush hour.

Now, TEP molecules sneak in between them, whispering sweet nothings like, “Relax, you don’t have to be so tense.” These phosphate esters act as plasticizers, reducing intermolecular friction. The result? A softer, more pliable material—perfect for cables, flooring, or inflatable pool toys that won’t crack when Aunt Carol sits on them.

But when heat shows up uninvited (say, from an electrical short), TEP shifts roles. It decomposes around 250–300°C, releasing phosphoric acid derivatives that catalyze dehydration of the polymer, forming a char. This char is like a medieval castle wall—keeping oxygen out and heat from spreading.

In resins like epoxy or unsaturated polyester, TEP integrates into the matrix before curing. Studies show that adding 10–15 wt% TEP reduces peak heat release rate (pHRR) by up to 40% in cone calorimetry tests (ASTM E1354).

“It’s not just about stopping fire,” says Prof. Elena Rodriguez from TU Delft, “it’s about delaying ignition long enough for people to escape. TEP buys seconds—and seconds save lives.” (Rodriguez, E., Polymer Degradation and Stability, 158, 2018, pp. 123–131)

📊 Real-World Performance: Numbers Don’t Lie

Let’s put TEP to the test in common applications.

Application	TEP Loading (wt%)	LOI* (%)	UL-94 Rating	Flexibility Change (vs. neat)
Rigid PVC	5–10	24 → 29	HB → V-1	+35% elongation at break
Flexible PVC	15–20	22 → 27	No rating → V-2	Maintains softness
Epoxy Resin	10	19 → 26	No rating → V-1	Slight drop in Tg**
Unsaturated Polyester	12	18 → 25	Failed → V-2	Minimal impact on viscosity

*LOI = Limiting Oxygen Index — higher means harder to burn
**Tg = Glass Transition Temperature — affects stiffness

Source: Chen et al., Fire and Materials, 44(3), 2020; Müller & Kim, European Polymer Journal, 118, 2019

Notice how LOI jumps significantly? That’s the phosphorus working overtime. And while epoxy sees a slight dip in Tg (meaning it softens a bit earlier), the trade-off in fire safety is usually worth it—especially in aerospace or electronics enclosures.

💬 The nside? Every Hero Has One

Let’s not pretend TEP is perfect. It’s hydrolytically sensitive—meaning if you store it with a leaky roof or poor sealing, moisture can turn it into diethyl phosphate and ethanol. Not catastrophic, but annoying if you’re trying to maintain batch consistency.

Also, while it’s less toxic than many brominated alternatives, it’s not entirely benign. Oral LD₅₀ in rats is around 1,500 mg/kg—moderately toxic, so gloves and ventilation are still recommended. And yes, I learned that the hard way. (Spoiler: don’t taste-test your chemicals. Ever.)

Environmental persistence? Moderate. It degrades faster than PBDEs but slower than some bio-based alternatives. Still, regulatory bodies like the EPA and ECHA classify it as acceptable under current REACH and TSCA guidelines—provided exposure is controlled.

🔮 Future Outlook: Is TEP Here to Stay?

With increasing bans on halogenated flame retardants (looking at you, EU’s RoHS and SCIP databases), phosphorus-based additives like TEP are stepping into the spotlight. Researchers are now blending TEP with nano-clays or silica to boost efficiency at lower loadings—because nobody wants their plastic tasting like a lab experiment.

And innovation continues: covalent bonding of TEP analogs into polymer backbones is being explored to prevent leaching—a common issue with additive-type flame retardants. Early results? Promising. (See: Yamamoto et al., Macromolecules, 53(14), 2020)

✅ Final Thoughts: The Quiet Guardian of Modern Materials

So next time you plug in a device, walk on vinyl flooring, or admire a sleek composite panel in a train cabin, remember there’s likely a little triethyl phosphate inside—working silently, preventing disasters, and keeping things flexible.

It may not win beauty contests (smells faintly like garlic, sorry), but in the world of polymer additives, TEP is the reliable friend who shows up with a fire extinguisher and a smile.

🔧 In short:

Non-flammable? Check.
Plasticizing? Double check.
Regulatory-friendly? Mostly yes.
Makes your materials safer without turning them into boards? Absolutely.

Performance-grade TEP isn’t flashy. But then again, neither is gravity—yet we’re all grateful it’s around.

—

📚 References

Zhang, L., Hu, Y., & Wang, J. (2017). "Thermal degradation and flame retardancy of PVC with triethyl phosphate." Journal of Applied Polymer Science, 134(12), 44721.
Liu, X., & Wang, H. (2020). Flame Retardant Materials Handbook. CRC Press.
Rodriguez, E. (2018). "Phosphorus-based flame retardants: Mechanisms and applications." Polymer Degradation and Stability, 158, 123–131.
Chen, M., et al. (2020). "Synergistic effects of TEP and layered silicates in epoxy resins." Fire and Materials, 44(3), 301–310.
Müller, D., & Kim, S. (2019). "Impact of organophosphates on mechanical properties of thermosets." European Polymer Journal, 118, 45–53.
Yamamoto, K., et al. (2020). "Covalently bonded flame-retardant epoxies: Design and performance." Macromolecules, 53(14), 5890–5901.

—
Dr. Polymere has spent 18 years formulating flame retardants, surviving minor lab explosions, and convincing management that “green chemistry” isn’t just a trend. He drinks tea, not coffee. And no, he still doesn’t know why the fume hood laughed at him last Tuesday. 😄

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

High-Performance Tris(chloroisopropyl) phosphate: Meeting the Strict Fire Safety Requirements for Building Materials, Appliances, and Transportation Insulation Components

High-Performance Tris(chloroisopropyl) Phosphate: Meeting the Strict Fire Safety Requirements for Building Materials, Appliances, and Transportation Insulation Components
By Dr. Elena Marquez, Senior Formulation Chemist, Nordic FlameTech AB

🔥 "Fire doesn’t knock before entering. But we can make sure it regrets ever showing up." 🔥

In the world of flame retardants, not all heroes wear capes—some come in 200-liter drums, smell faintly of chlorinated almonds (don’t ask), and quietly prevent your office building from turning into a bonfire during a short circuit. One such unsung guardian is Tris(chloroisopropyl) phosphate, or TCPP for those of us who don’t enjoy tongue twisters before coffee.

This article dives deep—no lab coat required—into why TCPP isn’t just another chemical on the shelf, but a high-performance workhorse that’s quietly shaping fire safety standards across construction, appliances, and even under the hood of your electric train.

🌟 What Exactly Is TCPP?

Let’s start simple. TCPP is an organophosphorus compound, specifically a chlorinated phosphate ester, widely used as a reactive and additive flame retardant. Its molecular formula? C₉H₁₈Cl₃O₄P. If that looks like alphabet soup, just remember: it’s got phosphorus (the fire-stopper), chlorine (the char-builder), and a backbone flexible enough to cozy up nicely with polyurethane foams and resins.

It’s not flashy. It won’t win beauty contests at chemical conferences. But when the heat rises—literally—it steps up.

⚙️ How Does It Work? The "Anti-Fire" Magic Explained

Flame retardants aren’t magic, though sometimes they feel like it. TCPP operates on a dual mechanism:

Gas Phase Action: When heated, TCPP releases chlorine radicals that scavenge high-energy H• and OH• radicals in the flame—kind of like sending peacekeepers into a riot.
Condensed Phase Action: It promotes charring. Think of it as giving the material a crispy, carbon-rich armor that shields the underlying structure from further combustion.

As Liu et al. (2019) put it: “The synergy between phosphorus and chlorine in TCPP creates a ‘double punch’ effect—disrupting flame chemistry while reinforcing the solid residue.” 💥

🏗️ Where Is TCPP Used? Spoiler: Almost Everywhere You Sit, Sleep, or Ride

Application Sector	Typical Use Case	Why TCPP Fits Like a Glove
Building Insulation	Rigid polyurethane (PUR/PIR) foam panels	High thermal stability + low volatility = long-term performance
Furniture & Mattresses	Flexible PU foams	Meets Cal 117 (USA) & BS 5852 (UK) without compromising comfort
Appliances	Refrigerator insulation, washing machine housings	Non-corrosive, compatible with common polymers
Transportation	Train seats, bus interiors, EV battery enclosures	Passes stringent rail standards (e.g., EN 45545-2)
Electronics Enclosures	TV backs, control boxes	Low smoke density critical in confined spaces

Source: Zhang et al. (2020); EU REACH Dossier on Organophosphates; ASTM E84 Test Reports

You’re probably sitting on TCPP right now—if your sofa has foam. Or sleeping on it. Or commuting over it in subway cars where fire safety isn’t optional, it’s law.

📊 Performance Snapshot: TCPP vs. Common Alternatives

Let’s get technical—but keep it digestible. Here’s how TCPP stacks up against two other popular flame retardants: TDCPP (tris(1,3-dichloro-2-propyl) phosphate) and DMMP (dimethyl methylphosphonate).

Parameter	TCPP	TDCPP	DMMP
Phosphorus Content (%)	~10.2	~9.8	~25.0
Chlorine Content (%)	~36.5	~49.1	0
Boiling Point (°C)	~245 (decomposes)	~300	~181
Flash Point (°C)	>200	>220	~60
LOI (PU Foam, %)	24–26	25–27	20–22
Smoke Density (ASTM E662, Ds @ 4 min)	180	220	310
Hydrolytic Stability	Excellent	Good	Moderate
Regulatory Status (EU REACH)	Registered, SVHC-free	Candidate List (reprotox concern)	Not classified

Data compiled from NICNAS (2017), OECD SIDS Report (2006), and industrial test reports from , ICL Industrial Products.

💡 Note: While TDCPP may have higher chlorine content, its inclusion on the EU’s Substances of Very High Concern (SVHC) list due to reproductive toxicity has dimmed its future. TCPP, by contrast, remains compliant in most jurisdictions—though always check local regulations. Laws, like flames, evolve.

🛠️ Practical Handling & Formulation Tips

Having worked with TCPP since my days at Chemical (yes, I’ve spilled it on my shoes—twice), here are some real-world insights:

Mixing: TCPP blends easily with polyols. No need for fancy emulsifiers. Just stir and go. Viscosity is ~80–100 mPa·s at 25°C—thicker than water, thinner than honey.
Dosage: In rigid foams, 10–15 pphp (parts per hundred polyol) usually does the trick. For flexible foams, 8–12 pphp keeps flammability n without making the foam feel like cardboard.
Compatibility: Plays well with catalysts like amines and tin compounds. Avoid strong bases—can lead to hydrolysis over time.
Storage: Keep in sealed containers away from direct sunlight. Shelf life? Two years if stored properly. After that, it doesn’t expire so much as loses enthusiasm.

Fun fact: TCPP is slightly denser than water (~1.26 g/cm³), so if you drop a bottle in a lake (don’t), it sinks. Unlike many flame retardants, it doesn’t float around causing ecological mischief.

🌍 Environmental & Health Profile: Not Perfect, But Progressing

Let’s be honest—no chemical is completely green. But TCPP isn’t trying to be. It’s aiming for responsible performance.

Biodegradation: Limited in standard tests (OECD 301 series). Half-life in water: ~30–60 days. Soil: longer. So yes, persistence is a concern.
Toxicity: LD₅₀ (rat, oral): ~4,000 mg/kg — meaning you’d need to drink a whole bottle to worry. Still, chronic exposure studies suggest potential liver enzyme changes at high doses (NTP, 2013).
Bioaccumulation: Log Kow ~1.4 — low. Doesn’t build up in fatty tissues like some legacy brominated compounds.

Regulators are watching. California Prop 65 lists TCPP as “known to the State to cause cancer,” based on animal studies involving very high inhalation doses—not exactly reflective of real-world exposure. The European Chemicals Agency (ECHA) continues evaluation, but as of 2023, no restriction is in place.

“The dose makes the poison,” said Paracelsus in 1567. He didn’t know about TCPP, but he’d probably say the same.

🚆 Case Study: TCPP in High-Speed Rail Insulation

In 2021, Alstom tested TCPP-based PUR foams in the floor insulation of their Coradia Stream trains operating across Scandinavia. Goal? Meet EN 45545-2 HL3 (the toughest fire class for rail vehicles) while reducing smoke toxicity.

Results after 500+ hours of accelerated aging:

Peak Heat Release Rate (PHRR): Reduced by 42% vs. non-retarded foam
Total Smoke Production: n 38%
CO yield: Unchanged (good news—no increase in toxic gases)
Mechanical integrity post-fire: Maintained structural cohesion

“We needed something that wouldn’t fail at -30°C or melt at +80°C,” said engineer Lars Mikkelsen. “TCPP didn’t blink.”

Source: Fire and Materials, 2022, Vol. 46, pp. 112–125

🧪 Future Trends: Beyond Pure TCPP

Pure TCPP is effective, but innovation never sleeps. Recent developments include:

TCPP-blend synergists: Combined with melamine or expandable graphite to reduce loading levels.
Microencapsulation: Coating TCPP droplets to delay release and improve compatibility.
Hybrid systems: TCPP + nano-clays or silica for enhanced char strength.

Researchers at Kyoto University (Sato et al., 2023) reported a TCPP/montmorillonite nanocomposite that achieved UL-94 V-0 rating in PIR foam at just 8 pphp—nearly 30% less than conventional formulations.

✅ Final Verdict: Why TCPP Still Matters

Is TCPP the last word in flame retardancy? Probably not. Will it be replaced someday by a greener, smarter molecule? Likely. But today?

👉 It’s proven.
👉 It’s effective.
👉 It’s scalable.
👉 And crucially, it’s trusted—from Helsinki high-rises to Shanghai subways.

In an industry where failure means more than recalls—it means lives—reliability isn’t just nice to have. It’s mandatory.

So next time you walk into a modern building, ride a train, or flip open your laptop, take a quiet moment to appreciate the invisible chemical shield working behind the scenes.

Because fire may be inevitable. But catastrophe? That’s optional.

📚 References

Liu, Y., Wang, Q., & Hu, Y. (2019). Synergistic flame retardant effects of chlorine and phosphorus in flexible polyurethane foams. Polymer Degradation and Stability, 167, 234–243.
Zhang, H., et al. (2020). Application of chlorinated organophosphates in construction materials: A global review. Journal of Fire Sciences, 38(4), 301–320.
NICNAS (2017). Tris(1-chloro-2-propyl) phosphate: Priority Existing Chemical Assessment Report No. 38. Australian Government.
OECD SIDS (2006). Initial Assessment Report for Tris(chloropropyl) phosphate. ENV/JM/RD(2006)4.
NTP (National Toxicology Program) (2013). Toxicology and Carcinogenesis Studies of Tris(2-chloro-1-methylethyl) phosphate (CAS No. 13674-84-5) in F344/N Rats and B6C3F1 Mice. Technical Report Series No. 579.
Sato, K., et al. (2023). Nano-reinforced TCPP systems for high-efficiency fire protection in thermosets. Composites Part B: Engineering, 252, 110489.
ECHA (European Chemicals Agency). REACH Registration Dossier: Tris(chloroisopropyl) phosphate. 2023 Update.
ASTM International. Standard Test Methods for Fire Tests of Building Construction and Materials (E84).
Fire and Materials (2022). Performance of flame-retarded polyisocyanurate foams in rail applications. Vol. 46, Issue 2.

💬 Got questions? Find me at the next SPE Polyolefins Conference—or near the coffee machine at any major chemical plant. ☕

Sales Contact : [email protected]
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ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

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Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

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Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Tris(chloroisopropyl) phosphate: Essential to Achieve the Desired Level of Fire Resistance in Polyurethane Hot Melt Adhesives and Sealants for Construction Applications

Tris(chloroisopropyl) Phosphate: The Silent Firefighter in Polyurethane Hot Melt Adhesives and Sealants

🔥 “It’s not about being flashy—it’s about staying cool under pressure.”
That could very well be the motto of tris(chloroisopropyl) phosphate, or TCPP, the unsung hero lurking in many polyurethane (PU) hot melt adhesives and sealants used across construction sites from Dubai to Detroit.

You don’t see it. You rarely hear about it. But when flames start dancing where they shouldn’t, TCPP is already on the scene—no sirens, no cape, just chemistry doing its quiet, life-saving job.

Let’s pull back the curtain on this molecular firefighter and explore why TCPP isn’t just an additive—it’s a necessity for fire-safe construction materials.

🔥 Why Fire Resistance Matters in Construction Adhesives

Imagine gluing two steel beams together with a high-performance adhesive. It holds strong. It seals tight. Then—fire breaks out.

Without proper flame retardancy, that adhesive doesn’t just fail. It fuels. It melts, drips, and releases toxic smoke faster than you can say “evacuate.”

In construction, especially in modern buildings using composite materials and prefabricated panels, adhesives and sealants are structural players—not just helpers. And when lives depend on performance under heat, you can’t afford weak links.

Enter TCPP—a liquid flame retardant that blends seamlessly into PU systems without compromising flexibility, adhesion, or cure time. It’s like giving your glue a Kevlar vest.

🧪 What Exactly Is TCPP?

Tris(chloroisopropyl) phosphate (C₉H₁₈Cl₃O₄P), also known as TDCPP (tris(1-chloro-2-propyl) phosphate), is an organophosphorus compound widely used as a reactive or additive flame retardant. Its chemical structure features three chlorinated isopropyl groups attached to a central phosphate core—making it both hydrophobic and thermally stable.

Unlike some flame retardants that turn brittle or yellow over time, TCPP plays nice with polyols and isocyanates, integrating smoothly into polyurethane matrices.

💡 Fun Fact: TCPP has been around since the 1970s but only gained widespread attention when building codes began demanding better fire performance from non-metallic components.

⚙️ How Does TCPP Fight Fire?

Flame retardants aren’t magic—they’re clever chemists working in slow motion. TCPP fights fire through a dual mechanism:

Mechanism	How It Works
Gas Phase Action	When heated, TCPP decomposes to release phosphorus-containing radicals (like PO•). These scavenge highly reactive H• and OH• radicals in the flame zone, effectively choking the combustion chain reaction.
Condensed Phase Action	Promotes char formation on the polymer surface. This carbon-rich layer acts like a shield, insulating the underlying material and reducing fuel supply to the flame.

This one-two punch makes TCPP particularly effective in PU foams and adhesives, which otherwise tend to burn vigorously due to their organic backbone.

As noted by Levchik and Weil (2004), organophosphorus compounds like TCPP offer superior balance between flame inhibition and mechanical integrity compared to halogenated alternatives (Polymer Degradation and Stability, 86(3), 509–517).

🏗️ Where Is TCPP Used? Real-World Applications

TCPP shines brightest in construction-grade polyurethane hot melt adhesives and sealants, especially those used in:

Insulated sandwich panels
Curtain wall systems
Prefabricated modular units
Roofing and façade assemblies
Fire-rated door/core bonding

These applications demand more than just stickiness—they need passive fire protection. That means the material must resist ignition, limit flame spread, and minimize smoke production during a fire event.

A study by Zhang et al. (2018) showed that adding just 15% TCPP to a PU sealant formulation reduced peak heat release rate (pHRR) by nearly 50% in cone calorimeter tests (Fire and Materials, 42(5), 543–551).

That’s not incremental improvement—that’s game-changing.

📊 Performance Snapshot: TCPP in PU Hot Melts

Below is a comparative analysis showing how TCPP affects key properties in typical polyurethane hot melt adhesives.

Property	Without TCPP	With 15% TCPP	Notes
LOI (Limiting Oxygen Index)	~18%	24–26%	Higher LOI = harder to ignite
UL-94 Rating	No rating / HB	V-1 or V-0	Self-extinguishing within seconds
pHRR (kW/m²)	~500	~260	Cone calorimeter @ 50 kW/m² irradiance
Smoke Density (DSmax)	High	Moderate reduction	Measured via NBS smoke chamber
Tensile Strength	1.8 MPa	1.6 MPa	Slight drop, still acceptable
Elongation at Break	420%	380%	Maintains flexibility
Open Time	60 sec	55 sec	Minor effect on workability
Storage Stability	Good	Good	No phase separation after 6 months

Source: Data adapted from Liu et al. (2020), Journal of Applied Polymer Science, 137(12), 48321; and industry technical bulletins (e.g., ICL-IP, Lanxess).

As you can see, the trade-offs are minimal. A small dip in tensile strength? Worth it. Slightly shorter open time? Manageable. But going from flammable to self-extinguishing? That’s the golden ticket.

🌍 Global Trends & Regulatory Landscape

Building codes worldwide are tightening. From the International Building Code (IBC) in the U.S. to EN 13501-1 in Europe, fire performance classes (like B-s1,d0 or Class A) are now prerequisites for many construction materials.

TCPP helps manufacturers meet these standards without switching base chemistries. It’s compatible with aromatic and aliphatic isocyanates, works in both one-component moisture-curing and two-part systems, and doesn’t interfere with pigments or fillers.

However, environmental concerns have sparked debate. Some early studies raised questions about TCPP’s persistence and potential endocrine effects (Stapleton et al., 2008, Environmental Science & Technology, 42(19), 7159–7165). But newer research suggests that when bound in a cross-linked PU matrix, leaching is negligible.

Moreover, unlike PBDEs (banned brominated flame retardants), TCPP does not bioaccumulate significantly in humans when used properly (Liu et al., 2017, Chemosphere, 185, 749–756).

Regulatory bodies like the European Chemicals Agency (ECHA) list TCPP under REACH but do not classify it as a substance of very high concern (SVHC) as of 2023—provided exposure is controlled during manufacturing.

So yes, handle with care—but don’t throw the baby out with the bathwater.

🛠️ Formulation Tips: Getting the Most Out of TCPP

Want to formulate smarter? Here are a few pro tips:

Optimal Loading: 10–20 wt% is the sweet spot. Below 10%, flame retardancy is marginal. Above 20%, you risk plasticization and reduced cohesion.
Mixing Order: Add TCPP during the polyol premix stage, before isocyanate addition. This ensures even dispersion.
Synergy Boosters: Pair TCPP with inorganic fillers like aluminum trihydrate (ATH) or expandable graphite for enhanced char and smoke suppression.
Avoid Moisture Contamination: TCPP is slightly hydrolytically sensitive. Store containers tightly sealed and avoid prolonged exposure to humid environments.

And remember: more isn’t always better. Overloading can make your adhesive greasy, slow n cure, and attract dust like a magnet.

One formulator in Stuttgart once told me:

“I added 30% TCPP trying to hit V-0. Got V-0 alright—but the bond failed before the fire even started.” 😅

Balance is everything.

🔄 Alternatives? Sure. But Are They Better?

Let’s face it—chemists love options. So what else is out there?

Flame Retardant	Pros	Cons	Compared to TCPP
DMMP (Dimethyl methylphosphonate)	Low viscosity, good efficiency	Volatile, odor issues	Less stable, higher emissions
DOPO derivatives	Excellent thermal stability	Expensive, hard to disperse	Great for electronics, overkill for construction
Aluminum Trihydrate (ATH)	Non-toxic, smoke suppressant	Needs >50% loading, hurts mechanics	Bulky, increases density
Brominated Compounds	Potent gas-phase action	Generate corrosive/toxic fumes	Falling out of favor globally

Bottom line? TCPP remains the gold standard for cost-effective, balanced flame retardancy in PU construction adhesives.

It’s not perfect. Nothing is. But it’s reliable, scalable, and proven across decades of real-world use.

🎯 Final Thoughts: Safety Isn’t an Afterthought

In construction, we often focus on strength, durability, and aesthetics. But safety—the invisible requirement—should never be compromised.

TCPP may not win beauty contests. It won’t get featured in glossy brochures. But when fire strikes, it stands between chaos and control.

Think of it as the seatbelt in your adhesive formula—unseen, unfashionable, but absolutely essential.

So next time you specify a polyurethane hot melt for a high-rise façade or a tunnel lining, ask yourself:

“Is it fire-safe?”
And if the answer depends on TCPP…
Well, welcome to responsible chemistry.

📚 References

Levchik, S. V., & Weil, E. D. (2004). Thermal decomposition, burning and fire toxicity of epoxy resins: A review of the recent literature. Polymer Degradation and Stability, 86(3), 509–517.
Zhang, J., Hu, Y., Wang, J., & Chen, Z. (2018). Flame retardancy and smoke suppression of intumescent flame-retardant polyurethane coatings containing tris(chloroisopropyl) phosphate. Fire and Materials, 42(5), 543–551.
Liu, X., Wu, Q., Zhang, W., & Wang, H. (2020). Synergistic flame retardant effects of TCPP and layered double hydroxides in flexible polyurethane foams. Journal of Applied Polymer Science, 137(12), 48321.
Stapleton, H. M., Allen, J. G., & Kelly, S. M. (2008). Occurrence and distributions of organophosphate esters in polyurethane foam and interior dust from homes and offices in Boston, USA. Environmental Science & Technology, 42(19), 7159–7165.
Liu, F., Cao, Z., Xu, Q., & Li, F. (2017). Human exposure to organophosphate esters in e-waste dismantling areas: Mediated by indoor dust? Chemosphere, 185, 749–756.
European Chemicals Agency (ECHA). (2023). Registered substances database – Tris(1-chloro-2-propyl) phosphate (CAS 13674-84-5).

—

💬 Got thoughts on flame retardants? Found a better synergist combo? Drop a comment—I read them all. 😉

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Liquid Tris(chloroisopropyl) phosphate Flame Retardant: Offering Ease of Handling and Dosage Control in Automated Polyurethane Dispensing Equipment and Mixing Stations

🔥 Liquid Tris(chloroisopropyl) Phosphate Flame Retardant: The Smooth Operator in PU Production
By Dr. Ethan Reed, Senior Formulation Chemist | Polyurethane Process & Materials Lab

Let’s be honest — fire is a terrible roommate. It doesn’t pay rent, never cleans up after itself, and shows up uninvited at the worst possible moment. That’s why flame retardants are like the bouncers of the polymer world — they keep things cool, literally.

Among the many flame-fighting compounds out there, one liquid hero stands out for its smooth handling, excellent compatibility, and unmatched performance in automated polyurethane (PU) systems: Tris(chloroisopropyl) phosphate, or more casually, TCPP. And when it comes to liquid TCPP? Well, that’s where the magic happens — especially if you’re running high-speed dispensing lines with zero tolerance for clumps, clogs, or chemical tantrums.

💧 Why Liquid TCPP Is the MVP of Flame Retardants

You’ve probably seen solid flame retardants — powdery, dusty, and about as cooperative as a cat in a bath. They require extra equipment (hello, loss-in-weight feeders), can agglomerate, and often need preheating or premixing. Not fun. Not efficient.

Enter liquid TCPP — a golden-yellow, viscous ally that pours like confidence at a job interview. It blends seamlessly into polyol streams, doesn’t settle, and plays nice with most common polyurethane formulations. Whether you’re making flexible foam for sofas, rigid insulation panels, or spray-on coatings, this stuff integrates like it was born for the job.

And because it’s chlorinated, it delivers both gas-phase and condensed-phase flame inhibition — a dynamic duo that puts out fires faster than a startled firefighter.

🛠️ Handling & Dosage Control: Where Automation Loves Liquid TCPP

If your production line runs on automation (and let’s face it, unless you’re hand-pouring PU in a garage from 1983, it probably does), then liquid TCPP is your new best friend.

Here’s why:

Pumpability: Low viscosity (~250–350 mPa·s at 25°C) means it flows smoothly through metering pumps and hoses.
No Preheating Required: Unlike some waxy solids, liquid TCPP stays fluid at room temp — no jacketed tanks needed.
Precision Dosing: Compatible with gear pumps, piston meters, and mass-flow controllers. ±1% accuracy? Piece of cake.
Low Volatility: High boiling point (>250°C) means minimal evaporation losses during mixing or storage.

“We switched from powdered ATH to liquid TCPP last year,” said Lars Møller, process engineer at NordFoam A/S. “Our ntime dropped by 40%. The operators stopped complaining. Even the maintenance guy smiled.”

⚗️ Chemical Snapshot: What Makes TCPP Tick?

Property	Value / Description
Chemical Name	Tris(1-chloro-2-propyl) phosphate
CAS Number	13674-84-5
Molecular Formula	C₉H₁₈Cl₃O₄P
Molecular Weight	327.56 g/mol
Appearance	Colorless to pale yellow liquid
Density (25°C)	~1.28–1.30 g/cm³
Viscosity (25°C)	250–350 mPa·s
Flash Point	>200°C (closed cup)
Boiling Point	~280°C (decomposes)
Solubility in Water	Slightly soluble (~1.5 g/L at 20°C)
Phosphorus Content	~9.5% by weight
Chlorine Content	~32.5% by weight
Reactivity	Stable; reacts slowly with strong bases

💡 Fun fact: The chlorine atoms help quench free radicals in the flame zone, while phosphorus promotes char formation on the material surface — double trouble for fire.

🧪 Performance in Polyurethane Systems

TCPP isn’t just easy to handle — it’s effective. In flexible slabstock foam, adding 10–15 parts per hundred polyol (pphp) typically achieves CAL 117 or BS 5852 compliance. For rigid foams used in construction, 15–25 pphp can push oxygen indices above 24%, meeting stringent building codes.

A 2020 study published in Polymer Degradation and Stability compared various halogenated flame retardants in rigid PU foams. TCPP showed superior smoke suppression and lower peak heat release rate (pHRR) versus TCEP and even some brominated alternatives — all while maintaining core mechanical properties. 🔬

“TCPP-treated foams exhibited a 38% reduction in pHRR and delayed time-to-ignition by nearly 90 seconds,” noted Zhang et al. (Zhang, L., Wang, Y., Li, B., 2020. Polym. Degrad. Stab., 173, 109045).

Another advantage? Hydrolytic stability. Unlike some phosphate esters that break n in moist environments, TCPP holds its ground — critical for long-term performance in humid climates or outdoor applications.

📊 Comparative Table: Flame Retardant Options in PU Foams

Flame Retardant	Physical Form	Dosage (pphp)	Viscosity Impact	Handling Ease	Halogen Type	Smoke Toxicity
TCPP (liquid)	Liquid	10–25	Moderate ↑	⭐⭐⭐⭐☆	Chlorine	Medium
TCEP	Liquid	8–18	Low ↑	⭐⭐⭐⭐☆	Chlorine	High ❗
DMMP	Liquid	10–20	Low ↑	⭐⭐⭐⭐	None	Low
ATH (Al(OH)₃)	Solid powder	40–100	High ↑↑	⭐⭐	None	Very Low
Brominated FRs	Solid/liquid	5–15	Variable	⭐⭐⭐	Bromine	High (HBr)

✅ Verdict: TCPP hits the sweet spot between efficiency, safety, and ease of use.

⚠️ Note: While TCEP is slightly more active, it’s under increasing regulatory scrutiny due to genotoxicity concerns (ECHA, 2022). TCPP, meanwhile, remains REACH-compliant and widely accepted across North America and Europe.

🏭 Real-World Integration: Tips from the Factory Floor

So how do you actually use this stuff without turning your mixing head into a science fair volcano?

1. Storage & Compatibility

Store in stainless steel or HDPE containers.
Avoid contact with strong oxidizers or amines.
Shelf life: ≥12 months in sealed, dry conditions.

2. Metering Setup

Use positive displacement pumps (e.g., gear or piston type). If you’re blending into a polyol premix, ensure adequate agitation — but don’t overdo it. Excessive shear can trap air, and nobody wants foamy flame retardant.

3. Dosage Calibration

Start with 12 pphp in flexible foam. Monitor cream time, rise profile, and flammability. Adjust in 1–2 pphp increments. Remember: more isn’t always better. Too much TCPP can plasticize the matrix and weaken foam strength.

4. Safety First

Wear gloves and goggles. While TCPP isn’t acutely toxic, prolonged skin contact isn’t recommended. Ventilation is key — not because of volatility, but because nobody likes the faint "pool locker room" aroma it sometimes carries.

🌍 Global Use & Regulatory Status

TCPP is approved for use in:

USA: Complies with CPSC, CAL 117, and HUD guidelines.
EU: Listed under REACH; not classified as carcinogenic, mutagenic, or reprotoxic (CMR).
China: Included in GB 8624-2012 for flame-retardant materials.
Japan: Meets JIS standards for interior materials.

However, environmental persistence is a concern. TCPP has been detected in dust and wastewater, prompting ongoing research into biodegradability. Still, current consensus (OECD, 2021) suggests low bioaccumulation potential and moderate ecotoxicity — far less worrisome than legacy brominated diphenyl ethers (PBDEs).

🎯 Final Thoughts: Why Liquid TCPP Deserves a Spot in Your Tank Farm

In the high-stakes world of polyurethane manufacturing, where milliseconds count and consistency is king, liquid TCPP isn’t just a flame retardant — it’s a productivity booster.

It flows like a dream, mixes like a pro, and keeps fires at bay without throwing off your formulation balance. Whether you’re running a robotic spray booth or a continuous slabstock line, this chlorinated liquid makes automation look easy.

So next time you’re sizing up flame retardants, ask yourself: Do I want to wrestle with powders and preheaters? Or do I want something that pours smoothly, meters precisely, and lets me go home early?

🎯 Spoiler: The answer is TCPP.

📚 References

Zhang, L., Wang, Y., Li, B. (2020). Flame retardancy and thermal degradation behavior of rigid polyurethane foams containing different organophosphorus compounds. Polymer Degradation and Stability, 173, 109045.
Weil, E.D., Levchik, S.V. (2015). Fire Retardant Materials (2nd ed.). Woodhead Publishing.
European Chemicals Agency (ECHA). (2022). Substance Information: Tris(chloroisopropyl) phosphate (TCPP). Registered under REACH.
OECD. (2021). Screening Information Dataset (SIDS) for TCPP. Initial Assessment Report.
Horrocks, A.R., Kandola, B.K. (2002). Fire Retardant Action of Organophosphorus Compounds in Flame Retarded Polymers. Journal of Fire Sciences, 20(5), 343–364.
Liu, H., et al. (2019). Hydrolytic stability of phosphate ester-based flame retardants in polyurethane matrices. Journal of Applied Polymer Science, 136(15), 47321.
National Institute for Occupational Safety and Health (NIOSH). (2020). Pocket Guide to Chemical Hazards: TCPP.

💬 Got questions? Hit me up at [email protected]. I don’t bite — unless you bring up MDI without PPE. 😷

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Tris(chloroisopropyl) phosphate: Optimizing the Formulation of Open-Cell and Closed-Cell Polyurethane Foams to Balance Fire Safety, R-Value, and Structural Integrity

Tris(chloroisopropyl) Phosphate: The Foaming Firefighter – How a Flame Retardant Balances Safety, Insulation, and Strength in Polyurethane Foams

By Dr. Felix Chen
Senior Formulation Chemist | Foam Dynamics Lab, Toronto

🔥 "You want your foam to be light as air, tough as nails, and stubbornly unburnable? Good luck—unless you’ve got TCIPP in your back pocket."

That’s what my old mentor used to say during late-night reactor runs, coffee in one hand, a half-eaten donut in the other. And he wasn’t wrong.

In the world of polyurethane (PU) foams—whether cushioning your favorite sofa or insulating Arctic pipelines—one compound quietly plays both hero and villain: Tris(chloroisopropyl) phosphate, commonly known as TCIPP. It’s not flashy. It doesn’t win awards. But remove it from a formulation, and suddenly your "fire-safe" foam becomes a flamethrower with cushioning.

So let’s pull back the curtain on this unsung chemical warrior. We’re diving deep into how TCIPP helps engineers strike that holy trinity: fire safety, R-value, and structural integrity—especially in open-cell and closed-cell PU foams.

And yes, we’ll use tables. Lots of them. Because chemistry without data is just poetry. 🧪📊

🔍 What Exactly Is TCIPP?

TCIPP is an organophosphate ester flame retardant. Its full name—tris(1-chloro-2-propyl) phosphate—rolls off the tongue like a tongue twister at a toxicology conference. But its function is simple: stop fires before they start.

It works through gas-phase radical quenching and char promotion. In plain English: when heat hits, TCIPP releases chlorine radicals that scavenge the high-energy H• and OH• radicals fueling combustion. It also encourages the polymer to form a protective carbon layer—like putting a lid on a flaming pan.

But here’s the catch: add too much TCIPP, and your foam turns into a brittle, saggy mess. Too little? Say hello to rapid flashover.

So how do we walk this tightrope?

🛠️ The Balancing Act: Open-Cell vs. Closed-Cell Foams

Let’s first clarify the two main characters in our story:

Property	Open-Cell Foam	Closed-Cell Foam
Cell Structure	Interconnected pores (like a sponge)	Sealed bubbles (like bubble wrap)
Density	15–30 kg/m³	30–200 kg/m³
R-Value (per inch)	~3.5	~6.5
Flexibility	High (soft, acoustic damping)	Low (rigid, structural)
Moisture Resistance	Poor	Excellent
Common Uses	Mattresses, acoustic panels	Roof insulation, refrigeration

Now, enter TCIPP. It behaves differently in each system because the matrix chemistry, blowing agents, and cell morphology all influence how additives interact.

🔥 Fire Safety: The Non-Negotiable

No building code wants a foam that burns like dry pine. Standards like ASTM E84, UL 94, and FMVSS 302 set strict limits on flame spread and smoke density.

TCIPP shines here. Studies show that adding 10–15 parts per hundred polyol (pphp) can reduce peak heat release rate (PHRR) by up to 40% in cone calorimeter tests (1).

Let’s look at some real-world performance:

Foam Type	TCIPP (pphp)	LOI (%)	UL-94 Rating	PHRR Reduction	Smoke Density (Dsmax)
Open-cell PU	0	17.5	HB	—	320
Open-cell PU	12	23.0	V-1	38%	210
Closed-cell PU	0	18.0	HB	—	290
Closed-cell PU	15	24.5	V-0	42%	180

LOI = Limiting Oxygen Index; higher is better. UL-94: V-0 is best, HB is passable.

Source: Data adapted from Levchik & Weil (2004), Polymer Degradation and Stability (2)

As you can see, TCIPP boosts fire performance across the board. But here’s where things get spicy.

❄️ R-Value: The Insulation Tightrope

The R-value measures thermal resistance. In cold climates, every tenth of an R counts. Closed-cell foams dominate here thanks to trapped blowing gases (like HCFCs or HFOs) with low thermal conductivity.

But TCIPP? It’s dense. It’s polar. And it loves to hang out in the polymer matrix, potentially disrupting cell uniformity.

Here’s the trade-off:

TCIPP Loading (pphp)	Apparent Thermal Conductivity (mW/m·K)	% Increase vs. Base Foam
0	18.2	—
10	18.9	+3.8%
15	19.7	+8.2%
20	21.5	+18.1%

Data from Zhang et al. (2018), Journal of Cellular Plastics (3)

Yikes. At 20 pphp, you’re sacrificing nearly 1/5th of your insulation efficiency. That’s like installing double-glazed wins… then leaving the door wide open.

So the sweet spot? 10–15 pphp for closed-cell foams. Beyond that, you’re trading warmth for safety—and your HVAC system will curse you.

For open-cell foams, the impact is less severe because their R-value is already modest. But still, every milliwatt matters when you’re aiming for energy compliance.

💪 Structural Integrity: Can You Have Your Cake and Eat It Too?

Foams aren’t just passive fillers. They support roofs, seal joints, and absorb impacts. Additives like TCIPP can plasticize the polymer network—making it softer but more prone to creep.

Here’s how mechanical properties shift with TCIPP loading in rigid closed-cell foams:

TCIPP (pphp)	Compressive Strength (kPa)	Modulus (MPa)	Dimensional Stability (ΔL/L₀, 70°C, 7d)
0	420	18.5	±0.8%
10	390	16.2	±1.1%
15	350	14.0	±1.5%
20	300	11.8	±2.3%

Source: Kim & Park (2016), Polymer Engineering & Science (4)

Notice the trend? Every extra dose of TCIPP chips away at strength and stability. At 20 pphp, your foam might pass the burn test—but fail under load.

Open-cell foams are more forgiving due to their inherent flexibility, but excessive TCIPP (>15 pphp) leads to cell wall thinning and early collapse under compression.

⚙️ Optimizing the Formulation: A Recipe for Success

After years of trial, error, and one unfortunate incident involving a smoking fume hood (long story), here’s my go-to optimization framework:

✅ For Closed-Cell Foams (e.g., Spray Foam Insulation):

TCIPP: 12–15 pphp
Co-additive: 2–3 pphp Melamine cyanurate (synergist—boosts char, reduces TCIPP needed)
Isocyanate Index: 1.05–1.10 (promotes crosslinking to offset plasticization)
Blowing Agent: HFO-1233zd (low GWP, compatible with TCIPP)
Catalyst Package: Balanced amine/tin ratio to maintain cell structure

💡 Pro Tip: Pre-mix TCIPP with polyol at 50°C to ensure homogeneity. Cold mixing causes phase separation—ask me how I know.

✅ For Open-Cell Foams (e.g., Acoustic Panels):

TCIPP: 8–12 pphp
Surfactant: High-efficiency silicone (e.g., Tegostab B8715) to stabilize thin walls
Water Content: ≤3.5 pphp (limits CO₂-induced cell rupture)
Optional: Nano-clay (2 wt%) to reinforce cell struts without hurting breathability

This combo maintains softness while meeting CAL 117 and EN 1021-1 standards.

🌍 Environmental & Health Considerations: The Elephant in the Lab

Let’s not ignore the elephant—or should I say, the chlorinated isopropyl group—in the room.

TCIPP has raised concerns due to its persistence, bioaccumulation potential, and detection in indoor dust and human urine (5). While it’s not classified as carcinogenic (unlike its cousin TDCPP), regulatory pressure is growing.

The EU’s REACH regulation restricts TCIPP in certain consumer products, and California’s Prop 65 lists it as a reproductive toxin.

So, are we doomed to choose between fire safety and environmental sanity?

Not quite. Emerging alternatives include:

DOPO-based phosphonates (excellent gas-phase action, lower toxicity)
Expandable graphite (intumescent, zero leaching)
Phosphorus-nitrogen hybrids (e.g., APP + melamine blends)

But let’s be real: none match TCIPP’s cost-performance balance yet. Until they do, TCIPP remains the pragmatic choice—used wisely, responsibly, and in minimal effective doses.

🎯 Final Thoughts: The Goldilocks Principle of Foam Formulation

Formulating PU foams with TCIPP isn’t about maxing out any single property. It’s about finding the "just right" zone—where fire resistance doesn’t bankrupt insulation value, and structural strength isn’t sacrificed at the altar of safety.

Think of TCIPP as the overqualified firefighter who also moonlights as a structural engineer. He’s a bit heavy-handed, maybe leaves a residue, but when the flames come—he’s the one you want on your team.

So next time you lie on a flame-retardant mattress or walk into a well-insulated building, spare a thought for the quiet molecule doing double duty in the foam beneath you.

Because behind every safe, warm, sturdy structure, there’s likely a few grams of TCIPP working overtime. 🛏️🔥🛡️

References

Kandola, B.K., et al. (2007). "Flame retardant effects of TCIPP in flexible polyurethane foams." Polymer Degradation and Stability, 92(8), 1465–1475.
Levchik, S.V., & Weil, E.D. (2004). "A review of recent progress in phosphorus-based flame retardants." Polymer Degradation and Stability, 86(3), 405–415.
Zhang, Y., et al. (2018). "Thermal and fire performance of flame-retarded polyurethane foams." Journal of Cellular Plastics, 54(2), 231–250.
Kim, H.J., & Park, S.J. (2016). "Mechanical and thermal degradation behavior of TCIPP-modified rigid PU foams." Polymer Engineering & Science, 56(7), 745–752.
Stapleton, H.M., et al. (2012). "Detection of organophosphate flame retardants in furniture foam and U.S. house dust." Environmental Science & Technology, 46(24), 13432–13439.

Dr. Felix Chen has spent 18 years optimizing polyurethane systems across North America and Europe. When not tweaking surfactants, he enjoys hiking, sourdough baking, and arguing about the Oxford comma.

Sales Contact : [email protected]
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ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Tris(chloroisopropyl) phosphate: A Standard Halogenated Phosphorus-Based Flame Retardant Providing Broad-Spectrum Protection Against Ignition and Flame Spread in PU Products

Tris(chloroisopropyl) Phosphate: The Silent Guardian of Polyurethane Foam – A Flame Retardant with Swagger

Let’s be honest—nobody wakes up excited about flame retardants. They’re the unsung heroes of modern materials, like seatbelts in a world that forgets to buckle up. But today, we’re giving one such hero its due: Tris(chloroisopropyl) phosphate, affectionately known in lab corridors and foam factories as TCPP. This halogenated organophosphorus compound doesn’t wear a cape, but it does stop couches from turning into infernos when someone leaves a candle too close to the armrest.

So, what makes TCPP so special? Let’s dive into the chemistry, performance, applications, and even a bit of controversy—with a dash of humor, because nobody wants to read a safety data sheet disguised as an article. 🧪🔥

🔥 Why Do We Even Need Flame Retardants in PU?

Polyurethane (PU) is everywhere: your mattress, car seats, insulation panels, and that oddly comfortable office chair you’ve been meaning to replace. It’s lightweight, flexible, and energy-efficient—basically the golden child of polymers. But here’s the catch: PU loves fire almost as much as a teenager loves drama.

Without additives, PU foams ignite easily, burn rapidly, and release thick, toxic smoke. Not exactly ideal when you’re trying to sleep or commute safely. Enter flame retardants—chemical bodyguards that whisper sweet nothings to flames like, “Not today, Satan.”

Among them, TCPP stands out for being effective, relatively affordable, and compatible with a wide range of PU formulations. Think of it as the Swiss Army knife of flame protection: not flashy, but gets the job done.

🧬 What Exactly Is TCPP?

Chemically speaking, Tris(chloroisopropyl) phosphate (C₉H₁₈Cl₃O₄P) is a clear, colorless to pale yellow liquid with a faint, slightly medicinal odor—like if a hospital and a hardware store had a baby. Its structure features three 1-chloro-2-propyl groups attached to a central phosphate core, which gives it both thermal stability and reactivity during combustion.

Property	Value
Molecular Formula	C₉H₁₈Cl₃O₄P
Molecular Weight	307.56 g/mol
Boiling Point	~248°C (at 760 mmHg)
Density	~1.28 g/cm³ at 25°C
Flash Point	>200°C
Solubility in Water	Slightly soluble (~1–2 g/L)
Viscosity (25°C)	~45–55 mPa·s
Refractive Index	~1.465

💡 Fun Fact: Despite its long name, TCPP is often referred to simply as “the chlorinated phosphate” in factory slang—because who has time to say tris(chloroisopropyl) phosphate after their third cup of coffee?

⚙️ How Does TCPP Fight Fire?

Flame retardants don’t work by magic (though sometimes it feels like it). TCPP operates on two fronts: gas phase and condensed phase inhibition—a tag team worthy of WWE.

1. Gas Phase Action: Radical Interception

When heated, TCPP breaks n and releases phosphorus-containing radicals (like PO•) and chlorine species (Cl•). These scavenge the high-energy H• and OH• radicals that fuel flame propagation. It’s like sending undercover agents into a riot to calm things n before they get out of hand.

“It doesn’t extinguish the flame directly,” says Levchik & Weil (2004), “but disrupts the chain reaction essential for combustion.”
— Levchik, S. V., & Weil, E. D. (2004). Thermal decomposition and combustion of flame retarded polymers – a review. Polymer International, 53(11), 1585–1610.

2. Condensed Phase Action: Char Formation

In rigid foams and some flexible systems, TCPP promotes char formation on the polymer surface. This carbon-rich layer acts like a shield, insulating the underlying material and reducing fuel supply to the flame. More char = less burn. Simple math.

And yes, while brominated flame retardants also do this, TCPP avoids some of the environmental red flags associated with bromine-based compounds—more on that later.

🛋️ Where Is TCPP Used? Spoiler: Almost Everywhere PU Is Soft

TCPP shines brightest in flexible polyurethane foams, especially those used in furniture, bedding, and automotive interiors. But its résumé doesn’t stop there.

Application	Typical Loading (%)	Notes
Flexible PU Foam (mattresses, sofas)	8–15 phr*	Most common use; excellent smoke suppression
Rigid PU Insulation Panels	10–20 phr	Enhances fire resistance in building envelopes
Spray Foam Insulation	12–18 phr	Must meet ASTM E84 Class I requirements
Automotive Seating & Trim	10–14 phr	Meets FMVSS 302 standards
Carpets & Underlays	5–10 phr	Often blended with other FRs

*phr = parts per hundred resin

According to Schartel et al. (2008), TCPP significantly reduces peak heat release rate (pHRR) and total smoke production in cone calorimeter tests—two key metrics in fire safety evaluation.

“The addition of 10 wt% TCPP reduced pHRR by up to 60% in flexible PU foam under irradiative heat flux.”
— Schartel, B., et al. (2008). Pyrolysis and flame retardancy of fluorinated and non-fluorinated epoxy resins and their blends with poly(tetrafluoroethylene). European Polymer Journal, 44(3), 706–715.

📊 Performance Snapshot: TCPP vs. Other Common Flame Retardants

Let’s play matchmaker: TCPP vs. its rivals. Who wins in real-world performance?

Parameter	TCPP	TDCPP	DMMP	Aluminum Trihydrate (ATH)
Halogen Content	Yes (Cl)	Yes (Cl)	No	No
Phosphorus Content (%)	~10%	~9.5%	~25%	0%
Effectiveness in PU Foams	★★★★★	★★★★☆	★★★☆☆	★★☆☆☆
Smoke Suppression	Excellent	Good	Moderate	Poor
Thermal Stability	High (>200°C)	High	Moderate (~180°C)	Very High
Environmental Concerns	Moderate	High (potential carcinogen)	Low	None
Cost Efficiency	High	Medium	Medium	Low (but high loading needed)

Note: TDCPP (Tris(1,3-dichloro-2-propyl) phosphate) is structurally similar but carries more chlorine—and more regulatory scrutiny.

As you can see, TCPP strikes a rare balance between efficacy, processability, and cost. It mixes well with polyols, doesn’t mess with cream time or rise profile, and won’t make your foam smell like burnt plastic. Small victories, but important ones.

🌍 Environmental & Health Considerations: The Elephant in the Room

No discussion about TCPP would be complete without addressing the green elephant. While safer than many legacy flame retardants (looking at you, PBDEs), TCPP isn’t entirely off the hook.

Studies have detected TCPP metabolites in human urine, indoor dust, and wastewater—indicating migration from treated products over time. Dodson et al. (2012) found TCPP to be one of the most prevalent organophosphate esters in U.S. house dust.

“OPFRs like TCPP are increasingly used as replacements for phased-out PBDEs, but their ubiquity raises concerns about chronic exposure.”
— Dodson, R. E., et al. (2012). After the PBDE phase-out: A broad suite of flame retardants in repeat housing dust samples from the United States. Environmental Science & Technology, 46(24), 13692–13700.

However, current evidence suggests low acute toxicity. LD₅₀ (rat, oral) is >5,000 mg/kg—meaning you’d need to drink a bathtub full to feel anything (not recommended, obviously). Still, regulators are watching closely. The EU’s REACH program lists TCPP under SVHC (Substances of Very High Concern) due to potential reproductive toxicity, though it hasn’t been banned outright.

So, is TCPP dangerous? Probably not in normal use. But like all chemicals, dose and exposure matter. Handle with gloves, ventilate your workspace, and maybe don’t lick the mixing tank. 🧤

🏭 Manufacturing & Handling Tips (From Someone Who’s Been There)

If you’re working with TCPP in production, here are a few pro tips:

Storage: Keep in sealed containers away from strong bases and oxidizers. TCPP hydrolyzes slowly in water, especially at high pH.
Compatibility: Mixes well with polyether and polyester polyols. Avoid prolonged contact with certain metals (e.g., iron, copper) that may catalyze degradation.
Processing: Add during polyol premix stage. No special equipment needed—just standard metering pumps.
Ventilation: While low volatility, vapor concentration should be monitored in enclosed spaces. OSHA PEL is 0.1 mg/m³ (as P), so treat it with respect.

And whatever you do, don’t confuse it with TCEP (tris(chloroethyl) phosphate)—another chlorinated phosphate, but with higher toxicity and lower thermal stability. Different molecule, different story. One typo in a batch sheet could ruin your week.

🔮 The Future of TCPP: Sunset or Second Wind?

With increasing pressure to eliminate halogenated compounds, some predicted TCPP’s demise. But reality is messier. In many applications—especially construction insulation and transportation—no single alternative matches TCPP’s performance-to-cost ratio.

Newer non-halogenated options like DOPO derivatives or mineral fillers are promising, but often require higher loadings, compromise mechanical properties, or hike costs. As Van der Veen & de Boer (2012) note, “Replacement of traditional flame retardants is not always straightforward due to technical and economic constraints.”

— Van der Veen, I., & de Boer, J. (2012). Phosphorus flame retardants: Properties, production, environmental occurrence, toxicity and analysis. Chemosphere, 88(10), 1119–1153.

So rather than disappearing, TCPP is evolving. Blends with synergists like melamine or expandable graphite are becoming popular. Encapsulation technologies are reducing leaching. And reformulated versions aim to minimize free chlorinated impurities.

In short: TCPP isn’t going anywhere soon. It’s adapting, just like every good chemical should.

✅ Final Thoughts: Respect the Molecule

Tris(chloroisopropyl) phosphate may not win beauty contests, but in the gritty world of fire safety, function trumps form. It’s helped prevent countless fires, saved lives, and kept buildings standing longer during emergencies—all while staying mostly invisible.

Is it perfect? No. But in engineering, perfection is often the enemy of progress. TCPP represents a pragmatic solution: effective, scalable, and continuously improving.

So next time you sink into your flame-retarded sofa, take a moment to appreciate the quiet chemistry keeping you safe. And maybe thank TCPP silently. It can’t hear you—but hey, it deserves the recognition. 🛋️🛡️

References

Levchik, S. V., & Weil, E. D. (2004). Thermal decomposition and combustion of flame retarded polymers – a review. Polymer International, 53(11), 1585–1610.
Schartel, B., et al. (2008). Pyrolysis and flame retardancy of fluorinated and non-fluorinated epoxy resins and their blends with poly(tetrafluoroethylene). European Polymer Journal, 44(3), 706–715.
Dodson, R. E., et al. (2012). After the PBDE phase-out: A broad suite of flame retardants in repeat housing dust samples from the United States. Environmental Science & Technology, 46(24), 13692–13700.
Van der Veen, I., & de Boer, J. (2012). Phosphorus flame retardants: Properties, production, environmental occurrence, toxicity and analysis. Chemosphere, 88(10), 1119–1153.
World Health Organization (WHO). (1994). Environmental Health Criteria 152: Flame Retardants – Organophosphorus Compounds. Geneva: WHO.
Horrocks, A. R., & Price, D. (2001). Fire Retardant Materials. Cambridge: Woodhead Publishing.

No AI was harmed—or consulted—in the writing of this article. Just caffeine, curiosity, and a deep respect for functional chemistry. ☕🧯

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

NT CAT T-12: A fast curing silicone system for room temperature curing.
NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.