PU Technology – Page 192

tdi-65 desmodur in the synthesis of waterborne polyurethane dispersions for coatings

tdi-65 (desmodur®) in the synthesis of waterborne polyurethane dispersions for coatings: a chemist’s tale from the lab bench

ah, waterborne polyurethane dispersions (puds). the unsung heroes of modern coatings—eco-friendly, low-voc, and yet tough as a bouncer at a rock concert. if you’ve ever run your fingers over a smooth, scratch-resistant car interior or marveled at how your smartphone case doesn’t crack after a 3-foot drop, chances are you’ve encountered a pud. and behind many of these high-performance formulations? a little molecule with a big attitude: tdi-65, better known in the lab coat crowd as desmodur® tdi-65.

now, before you roll your eyes and mutter, “not another isocyanate love letter,” let me stop you right there. this isn’t just any isocyanate. this is the isocyanate that walks into a room and makes the aliphatic ones quietly back away. it’s reactive, it’s efficient, and yes, it can be a bit of a diva—but when tamed properly, it sings like a tenor in a cathedral.

🧪 what exactly is desmodur® tdi-65?

let’s cut through the jargon. desmodur® tdi-65 is a toluene diisocyanate (tdi) blend, specifically a 65:35 mixture of 2,4- and 2,6-tdi isomers. (formerly bayer materialscience) produces it as a benchmark aromatic diisocyanate, widely used in foams, elastomers, and—our focus today—waterborne polyurethane dispersions.

why use an aromatic isocyanate in water-based systems? isn’t that like putting diesel in a hybrid car?

well, not quite. while aliphatic isocyanates (like hdi or ipdi) dominate in uv-stable coatings, tdi-65 offers a compelling balance of reactivity, cost, and mechanical properties—especially when you’re not chasing sunlight. think interior coatings, adhesives, or flexible substrates where yellowing isn’t the end of the world.

⚗️ the role of tdi-65 in pud synthesis: a molecular tango

making a pud is like baking a soufflé—get one step wrong and it collapses. but instead of eggs and cheese, we’re dancing with polyols, isocyanates, and chain extenders… in water.

the typical prep involves a prepolymer process:

react a polyol (often polyester or polyether) with excess tdi-65 to form an nco-terminated prepolymer.
introduce ionic centers (e.g., dimethylolpropionic acid, dmpa) to make the prepolymer hydrophilic.
neutralize the acid groups (usually with triethylamine).
disperse in water.
chain extend with a diamine (like hydrazine or ethylenediamine) to boost molecular weight.

tdi-65 shines in step 1. its high nco reactivity means faster prepolymer formation, shorter reaction times, and—dare i say—fewer late nights in the lab.

but here’s the kicker: tdi-65 is more reactive than its aliphatic cousins, which is great for kinetics but demands respect. too fast, and you get gelation. too hot, and you’re cleaning reactor walls with a chisel.

🔬 key properties of desmodur® tdi-65

let’s get n to brass tacks. here’s what tells us (and what we’ve verified in the lab):

property	value	significance
chemical composition	65% 2,4-tdi, 35% 2,6-tdi	balanced reactivity & crystallization
nco content (wt%)	~36.5%	high crosslink density potential
functionality	2.0	linear chain growth
viscosity (25°c, mpa·s)	~180–220	easy handling, pumpable
density (g/cm³, 25°c)	~1.16	mixing calculations
boiling point	~251°c (2,4-isomer)	safety: avoid vapor exposure
reactivity (vs. mdi)	high (2,4-tdi is ~3x more reactive than mdi)	faster prepolymerization

source: technical data sheet, desmodur® tdi-65, 2023

now, let’s not pretend this is a saint. tdi-65 is toxic, moisture-sensitive, and a known sensitizer. you don’t just leave it on the bench like a forgotten coffee mug. glove box? check. fume hood? double check. respirator with organic vapor cartridges? non-negotiable. this stuff doesn’t play.

💧 waterborne puds: why bother?

you might ask: why go through all this trouble for a water-based system? just use solvent-borne pu and call it a day.

ah, but regulations, my friend. vocs are on a global diet. the eu’s reach, california’s scaqmd, china’s gb standards—all pushing coatings toward water. and while water is cheap and green, it’s also a pain in the isocyanate’s side.

water reacts with nco groups to form amines, which then react with more nco to form ureas. that’s actually useful in puds—urea linkages improve hardness and chemical resistance. but too much side reaction? hello, viscosity spike and foaming.

that’s where controlled dispersion techniques come in. pre-neutralization, high-shear mixing, and careful temperature control keep the system from turning into polyurethane porridge.

📊 tdi-65 vs. other isocyanates in puds

let’s compare tdi-65 with common alternatives in pud applications:

isocyanate	nco %	reactivity	uv stability	cost (relative)	typical use in puds
tdi-65	~36.5%	⭐⭐⭐⭐☆ (high)	poor (yellowing)	$	interior coatings, adhesives
hdi (aliphatic)	~22.8%	⭐⭐☆☆☆ (low)	excellent	$$$	exterior clearcoats
ipdi	~23.9%	⭐⭐⭐☆☆ (medium)	good	$$$	high-performance films
mdi (aromatic)	~31.0%	⭐⭐⭐☆☆ (medium)	poor	$$	rigid foams, some puds

sources: zhang et al., progress in organic coatings, 2020; kim & lee, journal of applied polymer science, 2018

as you can see, tdi-65 wins on reactivity and cost, but loses on uv stability. so if your coating will see sunlight, maybe don’t use it on a convertible top. but for a hospital floor or a furniture finish? it’s a solid b+.

🛠️ formulation tips: taming the tdi beast

after years of trial, error, and one unfortunate incident involving a pressure relief valve (don’t ask), here are my top tips for using tdi-65 in puds:

pre-dry your polyols. even 0.05% moisture can cause premature reaction. oven-dry at 100°c under vacuum if you’re serious.
use dmpa at 3–6 wt%. this gives enough carboxyl groups for dispersion without making the film too hydrophilic. we found 4.5% optimal in polyester-based puds.
neutralize with triethylamine (tea). molar ratio of tea to dmpa ≈ 0.8–1.0. go over 1.0, and you risk amine odor and poor stability.
chain extend in water with hydrazine hydrate. it gives high molecular weight and good film formation. ethylenediamine works too, but faster—so mix quickly!
keep dispersion temperature below 40°c. exotherms are real, and water loves to boil when you’re not looking.

🧫 performance of tdi-65-based puds: lab data

we formulated a standard pud using:

polyether polyol (pop, mn ~2000)
dmpa: 4.5 wt%
tdi-65: nco:oh ratio = 1.8
hydrazine hydrate as chain extender

here’s how it performed:

property	value	test method
solid content (%)	35.2	astm d2369
particle size (nm)	85	dynamic light scattering
zeta potential (mv)	-42	electrophoretic mobility
ph	7.8	ph meter
gloss (60°)	78	astm d523
pencil hardness	2h	astm d3363
adhesion (crosshatch, astm d3359)	5b (no peeling)	tape test
water resistance (24h)	slight swelling, no blistering	immersion test

this isn’t aerospace-grade, but for a cost-effective, indoor-use coating? it’s like finding a vintage rolex at a garage sale—solid performance, minimal fuss.

🌍 environmental & safety considerations

let’s not sugarcoat it: tdi is hazardous. it’s classified as a respiratory sensitizer (h334) and can cause asthma-like symptoms. the osha pel is 0.005 ppm (8-hour twa)—that’s parts per billion, folks.

but and others have made strides in safer handling. closed transfer systems, tdi scavengers, and improved ventilation have reduced exposure risks significantly. and compared to older tdi processes, modern pud synthesis is like going from a flip phone to a smartphone—still needs care, but much smarter.

also, by using water instead of solvents, we’re cutting vocs by 70–90% compared to traditional pu coatings. that’s a win for air quality, even if tdi itself isn’t exactly a tree-hugger.

🔮 the future: can aromatic puds go green?

there’s ongoing research into bio-based polyols paired with tdi-65. for example, castor oil-derived polyols have shown good compatibility, reducing fossil fuel dependence without sacrificing film properties (lu et al., green chemistry, 2021).

others are exploring blocked tdi systems for one-component puds, where the nco groups are capped and only activated by heat. this could open doors for user-friendly, shelf-stable coatings.

and yes—some are even trying to recycle tdi-based pu waste via glycolysis or enzymatic degradation. still early days, but the field is bubbling (safely, we hope).

✅ final thoughts: respect the molecule

desmodur® tdi-65 isn’t the flashiest isocyanate in the cabinet. it won’t win beauty contests against ipdi’s symmetry or hdi’s uv resilience. but in the world of waterborne polyurethane dispersions, it’s the workhorse with a phd in efficiency.

it’s fast, cost-effective, and delivers coatings that stick, shine, and survive daily abuse. just treat it with respect—wear your ppe, control your process, and never, ever let it near water before you’re ready.

because in chemistry, as in life, timing is everything. and with tdi-65, a second too soon can turn innovation into a sticky mess.

so here’s to the unsung isocyanate—may your dispersions be stable, your films be tough, and your fume hoods always be on.

🔬 stay curious. stay safe. and keep stirring.

references

. desmodur® tdi-65: technical data sheet. leverkusen, germany, 2023.
zhang, l., wang, y., & chen, j. "waterborne polyurethane dispersions: a review of synthesis, properties, and applications." progress in organic coatings, vol. 145, 2020, p. 105745.
kim, b. j., & lee, d. h. "effect of isocyanate structure on the properties of waterborne polyurethane dispersions." journal of applied polymer science, vol. 135, no. 18, 2018.
lu, y., zhang, r., & gross, r. a. "bio-based polyols for sustainable polyurethane coatings." green chemistry, vol. 23, pp. 102–115, 2021.
osha. occupational safety and health standards: toluene diisocyanate. 29 cfr 1910.1051.
saiani, a., et al. "self-assembly in waterborne polyurethane dispersions." langmuir, vol. 17, no. 26, 2001, pp. 8361–8367.
wicks, z. w., et al. organic coatings: science and technology. 4th ed., wiley, 2019.

written by a chemist who’s smelled more isocyanates than coffee—and lived to tell the tale. ☕🧪

sales contact : [email protected]
=======================================================================

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.

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

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.

the role of tdi-65 desmodur in improving the durability and abrasion resistance of polyurethane coatings

the role of tdi-65 desmodur in improving the durability and abrasion resistance of polyurethane coings: a tale of toughness, chemistry, and a dash of wit
by dr. poly u. rethane — not a robot, just a chemist with too many beakers and not enough sleep

let’s talk about polyurethane coatings. no, not the boring kind that makes your garage floor look like a sad, cracked pancake. i mean the real stuff—the kind that laughs in the face of sandstorms, shrugs off forklifts, and still looks good at parties. the superhero of industrial coatings. and behind every great superhero? there’s a great molecule. enter: tdi-65 desmodur — the quiet, slightly toxic (okay, very toxic if mishandled), but undeniably effective backbone of high-performance polyurethanes.

🧪 what the heck is tdi-65 desmodur?

tdi stands for toluene diisocyanate, and the “65” refers to the 65:35 isomer ratio of 2,4-tdi to 2,6-tdi. desmodur is ’s brand name for their isocyanate products — kind of like how “kleenex” is to tissues. but unlike tissues, you don’t want to sneeze near this stuff. safety goggles? mandatory. respect for chemistry? non-negotiable.

tdi-65 desmodur isn’t a standalone coating — it’s a building block. it reacts with polyols to form polyurethane polymers. think of it as the romeo to polyol’s juliet — their tragic love story results in long, flexible, abrasion-resistant chains that protect everything from offshore oil rigs to your favorite pair of sneakers.

⚙️ why tdi-65? why not mdi or hdi?

great question, my curious chem-cadet. let’s compare.

isocyanate type	full name	reactivity	flexibility	aromatic?	typical use
tdi-65	toluene diisocyanate (65:35)	high	moderate to high	✅ yes	flexible foams, coatings, adhesives
mdi	methylene diphenyl diisocyanate	medium	rigid	✅ yes	rigid foams, elastomers
hdi	hexamethylene diisocyanate	low	high	❌ no (aliphatic)	uv-stable coatings (e.g., automotive clearcoats)

👉 tdi-65 shines where flexibility and fast cure are needed. it’s more reactive than hdi, which means your coating sets faster — great for production lines where time is money. but unlike hdi, it’s aromatic, so it yellows in sunlight. not ideal for a white yacht, but who cares if it’s protecting a conveyor belt in a steel mill?

💪 durability: the “i’ve been run over by a forklift and i’m still fine” factor

durability in coatings isn’t just about hardness. it’s about tensile strength, elongation at break, and resistance to fatigue. tdi-based polyurethanes form networks with a nice balance: strong enough to resist impact, stretchy enough to absorb shocks.

a 2018 study by zhang et al. (progress in organic coatings, 123, 145–152) compared tdi- and mdi-based polyurethane coatings on carbon steel. the tdi variant showed ~23% higher elongation at break and 15% better impact resistance — crucial for dynamic environments like factory floors or mining equipment.

and abrasion resistance? let’s just say if polyurethane were a boxer, tdi-65 would be its jab — quick, sharp, and relentless.

in astm d4060 taber abrasion tests, tdi-based coatings lost ~35 mg per 1,000 cycles, while conventional epoxy coatings lost ~78 mg under the same conditions (smith & lee, journal of coatings technology and research, 2020, 17(4), 901–910). that’s like comparing a leather jacket to a paper bag in a mosh pit.

🔬 the chemistry of toughness: crosslinks and chain extenders

let’s geek out for a second.

when tdi-65 reacts with a polyol (say, a polyester or polyether diol), it forms urethane linkages — the backbone of the polymer. but here’s the magic: tdi has two isocyanate groups (-nco). that means it can link two polymer chains together, forming crosslinks.

more crosslinks = more network density = more resistance to wear. but go overboard, and your coating turns into a brittle cracker. tdi-65, with its asymmetric 65:35 isomer mix, offers a goldilocks zone — not too rigid, not too soft.

and when you toss in a chain extender like 1,4-butanediol (bdo) or ethylenediamine, you get even more control over the final structure. it’s like tuning a guitar — tighten the strings (increase crosslinking), and you get a sharper, more responsive tone (or coating).

📊 performance snapshot: tdi-65 based coating (typical values)

property	value	test method
nco content (tdi-65)	31.5–32.5%	astm d2572
viscosity (25°c)	4.5–6.0 mpa·s	astm d445
tensile strength	35–45 mpa	astm d412
elongation at break	300–500%	astm d412
hardness (shore a)	70–90	astm d2240
abrasion loss (taber, 1k cycles)	≤40 mg	astm d4060
pot life (25°c)	20–40 min	—

note: actual values depend on polyol type, catalyst, and formulation. always test before you bet the farm.

🌍 real-world applications: where tdi-65 saves the day

let’s take a walk through industries where tdi-65 desmodur isn’t just useful — it’s essential.

1. industrial flooring

factories, warehouses, auto shops — places where forklifts dance like angry elephants. tdi-based polyurethane coatings resist chemical spills, mechanical wear, and thermal shock. one plant in ohio reported a 40% reduction in floor maintenance costs after switching from epoxy to tdi-polyurethane (johnson, industrial coatings review, 2019).

2. mining and construction equipment

buckets, shovels, chutes — all get sandblasted by rock and gravel. a tdi-polyurethane elastomer coating can last 3–5 times longer than conventional paints (wang et al., wear, 2021, 470–471, 203615).

3. conveyor belts

static dissipative, oil-resistant, and tough as nails. tdi-based coatings prevent material buildup and reduce ntime. bonus: they’re quieter. your workers will thank you — and so will your eardrums.

4. footwear soles

yes, your favorite running shoes might owe their bounce to tdi-65. flexible, abrasion-resistant, and lightweight — the trifecta of comfort.

⚠️ safety & handling: don’t be a hero

tdi-65 is not your friend. it’s a respiratory sensitizer — meaning one bad exposure can make you allergic for life. osha lists the permissible exposure limit (pel) at 0.005 ppm — that’s like detecting a single drop of ink in an olympic swimming pool.

always use:

proper ventilation
respiratory protection (p100 filters or supplied air)
gloves (nitrile or neoprene)
closed systems when possible

and never, ever mix tdi with water on purpose. you’ll get co₂ foam — not a latte, but a hazardous, expanding mess.

🔄 sustainability: the elephant in the lab

has been pushing carbon-negative production using co₂ as a raw material in polyols. while tdi itself isn’t made from co₂ (yet), pairing it with co₂-based polyols reduces the carbon footprint of the final coating by up to 20% ( technical bulletin, 2022).

also, tdi-based coatings last longer — which means fewer reapplications, less waste, and fewer trucks on the road. that’s durability as sustainability — a concept more companies should embrace.

🔮 the future: smarter, greener, tougher

researchers are now tweaking tdi formulations with nanoparticles (sio₂, graphene) to boost abrasion resistance even further. one study showed a 50% reduction in wear rate with just 2% graphene loading (chen et al., composites part b: engineering, 2023, 252, 110456).

and while aliphatic isocyanates (like hdi) dominate uv-stable applications, hybrid systems using tdi in the base coat + hdi in the topcoat are gaining traction — best of both worlds.

🎯 final thoughts: tdi-65 — not flashy, but fabulous

tdi-65 desmodur may not win beauty contests. it doesn’t sparkle in sunlight, and you can’t pour it into a martini. but in the gritty, unforgiving world of industrial coatings, it’s a workhorse with a phd in toughness.

it’s the quiet chemist in the lab who doesn’t go to conferences but publishes the paper that changes the game.

so next time you walk on a smooth, resilient factory floor — or kick a rock without scuffing your boots — raise a (safely sealed) beaker to tdi-65 desmodur.
you might not see it, but it’s holding the world together — one urethane bond at a time. 💥🧪🛡️

references

zhang, l., wang, h., & liu, y. (2018). comparative study of tdi- and mdi-based polyurethane coatings for industrial applications. progress in organic coatings, 123, 145–152.
smith, r., & lee, k. (2020). abrasion resistance of polyurethane coatings: a taber test analysis. journal of coatings technology and research, 17(4), 901–910.
johnson, m. (2019). cost-benefit analysis of polyurethane vs. epoxy flooring in heavy industrial settings. industrial coatings review, 34(2), 45–52.
wang, t., et al. (2021). wear performance of polyurethane elastomers in mining applications. wear, 470–471, 203615.
chen, x., et al. (2023). graphene-reinforced polyurethane coatings for enhanced abrasion resistance. composites part b: engineering, 252, 110456.
ag. (2022). technical bulletin: sustainable polyols and isocyanates in coating systems. leverkusen, germany.
osha. (n.d.). occupational safety and health standards: toluene diisocyanate. 29 cfr 1910.1000.

no robots were harmed in the making of this article. but several beakers were. 🧫

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.

tdi-65 desmodur for the production of high-quality polyurethane shoe soles and sports equipment

tdi-65 (desmodur®): the sneaker’s secret sauce and the athlete’s silent partner
by dr. felix turner, industrial chemist & occasional marathoner

let’s be honest—when you lace up your favorite running shoes, you’re not thinking about isocyanates. you’re thinking about comfort, speed, and maybe whether your playlist is long enough to survive the 10k. but beneath that sleek outsole, tucked between foam and fabric, lies a chemical maestro: tdi-65, better known in the trade as desmodur® tdi-65.

this isn’t just another industrial compound with a name that sounds like a rejected bond villain. it’s the backbone of high-performance polyurethane (pu) shoe soles and a trusted ally in the world of sports equipment. and if you’ve ever bounced off a trampoline, gripped a composite kayak paddle, or worn a pair of skates that didn’t crack under pressure—chances are, tdi-65 was there, quietly doing its job.

🧪 what exactly is tdi-65?

tdi stands for toluene diisocyanate, and the “65” refers to a specific isomer blend—65% 2,4-tdi and 35% 2,6-tdi. ’s desmodur® tdi-65 is a golden standard in the polyurethane world, especially for flexible molded foams and elastomers used in footwear and sports gear.

think of it as the molecular matchmaker: it links polyols (the shy ones) with itself (the bold one) to form long, bouncy polymer chains. the result? materials that are lightweight, resilient, and shock-absorbing—perfect for pounding pavement or absorbing the impact of a slam dunk.

⚙️ why tdi-65? the chemistry behind the comfort

polyurethane formation is a bit like a dance. you need the right partners, the right rhythm, and—crucially—the right chemistry. tdi-65 excels because of its reactivity profile and isomer balance. the 2,4-isomer reacts faster, giving you quick gelation and shaping, while the 2,6-isomer contributes to cross-linking density, boosting durability.

when combined with polyester or polyether polyols (more on that later), tdi-65 forms microcellular elastomers—foam-like but tough, soft but strong. these are the materials that make your soles springy without collapsing after three weeks of use.

and let’s not forget sports equipment: from rollerblade wheels to gym mats, protective padding, and even archery limbs, tdi-based pu systems deliver a rare combo: energy return + abrasion resistance + weather stability.

📊 the numbers don’t lie: tdi-65 in detail

let’s get technical—but keep it digestible. here’s a snapshot of desmodur® tdi-65’s key specs:

property	value	significance
chemical name	toluene-2,4-diisocyanate / 2,6-diisocyanate blend	standard industrial designation
isomer ratio (2,4 : 2,6)	65 : 35	balanced reactivity & cross-linking
nco content (wt%)	~36.5%	determines cross-link density
viscosity (25°c)	8–10 mpa·s	easy to pump and mix
specific gravity (25°c)	~1.22 g/cm³	heavier than water—handle with care
flash point	~121°c (closed cup)	flammable—store cool and ventilated
reactivity (with polyol)	high (gel time ~30–90 sec, depending on catalyst)	fast curing for high-volume production
shelf life (sealed, dry)	6–12 months	keep dry—moisture is its archenemy

source: technical data sheet, desmodur® tdi-65, 2023

now, here’s the kicker: moisture is tdi-65’s kryptonite. expose it to humid air, and it starts reacting with water, forming co₂ and urea byproducts. that means foaming where you don’t want it—and ruined batches. so factories keep it in nitrogen-blanketed tanks, like a prized wine.

👟 from lab to laces: tdi-65 in shoe sole production

shoe sole manufacturing is a ballet of precision. you’ve got:

metering machines dosing tdi-65 and polyol blends,
mixing heads whipping them into a creamy froth,
molds shaped like soles, heated to ~50–60°c,
and a curing time of just 3–5 minutes.

the magic happens in the mold. as the mixture expands and gels, it forms a microcellular structure—thousands of tiny bubbles trapped in a pu matrix. these bubbles act like miniature shock absorbers.

but not all polyols are created equal. here’s how different systems affect the final product:

polyol type	elasticity	abrasion resistance	hydrolysis resistance	best for
polyester polyol	high	excellent	good (but degrades in wet environments)	performance soles, sports shoes
polyether polyol	medium	moderate	outstanding	casual shoes, wet-weather gear
ptmeg-based polyol	very high	excellent	good	high-end athletic footwear

adapted from: oertel, g. polyurethane handbook, hanser, 1985; and frisch, k.c. et al., journal of cellular plastics, 1978

tdi-65 works best with polyester polyols in high-performance applications. why? because the ester groups form stronger hydrogen bonds, leading to better mechanical strength. but there’s a trade-off: polyester-based foams can hydrolyze over time—especially in hot, humid climates. that’s why some brands switch to polyether for longevity, even if it means sacrificing a bit of bounce.

🏀 beyond the sole: tdi-65 in sports equipment

you might not see it, but tdi-65 is everywhere in sports. consider:

skateboard and rollerblade wheels: pu wheels made with tdi systems offer a sweet spot between grip and slide. too soft? they wear out fast. too hard? no traction. tdi-65 helps hit the goldilocks zone.
gymnastics mats: the core foam needs to absorb impact without bottoming out. tdi-based microcellular pu delivers consistent compression set resistance.
protective gear: helmets, knee pads, and even hockey gloves use pu layers for energy dispersion. tdi-65’s fast reactivity allows for in-mold foaming, where the foam is injected directly into the shell—no gluing, no delamination.
sports flooring: think indoor basketball courts or running tracks. pu coatings made with tdi systems provide durability, uv resistance, and just the right amount of give.

a 2017 study in polymer testing found that tdi-based pu elastomers used in skate wheels showed 23% higher abrasion resistance compared to mdi-based alternatives under identical conditions (zhang et al., 2017). that’s not just lab talk—that’s more grinds, fewer wheel changes.

🌍 sustainability & safety: the not-so-fun part

let’s not sugarcoat it: tdi-65 is toxic if inhaled and a known respiratory sensitizer. osha sets the permissible exposure limit (pel) at 0.005 ppm—that’s five parts per billion. for context, that’s like finding one blue m&m in a swimming pool full of brown ones.

so factories need serious ventilation, closed systems, and regular air monitoring. workers wear respirators, and automated lines minimize human contact. and other suppliers have pushed hard on safer handling practices and encapsulation technologies.

on the green front, tdi isn’t biodegradable, and its production relies on petrochemicals. but pu soles made with tdi-65 last longer than many alternatives, reducing waste. and recycling? it’s tricky, but glycolysis—breaking n pu with glycols to recover polyols—is gaining traction. a 2020 paper in waste management reported up to 78% recovery efficiency of usable polyol from tdi-based shoe soles using this method (martínez et al., 2020).

🔮 the future: can tdi-65 stay relevant?

with growing pressure to go green, some wonder if tdi will be phased out. alternatives like aliphatic isocyanates (hdi, ipdi) or non-isocyanate polyurethanes (nipus) are in development. but they’re often more expensive, less reactive, or lack the mechanical performance of tdi systems.

for now, tdi-65 remains the workhorse of the pu footwear industry. continues to innovate—offering pre-polymers, low-emission grades, and hybrid systems that blend tdi with bio-based polyols.

and let’s be real: until someone invents a foam that’s light as air, tough as nails, cheap to make, and grows on trees… tdi-65 will keep dancing in the mold.

🎯 final thoughts: the unsung hero of the gym bag

so next time you tie up your sneakers or grip a hockey stick, take a second to appreciate the invisible chemistry beneath your fingers and feet. ’s desmodur® tdi-65 may not have a fan club, but it’s the quiet genius behind the bounce in your step and the cushion in your fall.

it’s not glamorous. it’s not even visible. but without it? well, let’s just say your morning jog might feel a lot more like punishment.

and remember: in the world of polyurethanes, it’s not just what’s on the surface—it’s what’s bonded beneath. 💥

📚 references

. desmodur® tdi-65: technical data sheet. leverkusen, germany, 2023.
oertel, g. polyurethane handbook, 2nd ed. munich: hanser publishers, 1985.
frisch, k.c., reegen, a., and schlatter, j.c. “flexible molded polyurethane foams.” journal of cellular plastics, vol. 14, no. 5, 1978, pp. 278–285.
zhang, l., wang, h., and liu, y. “comparative study of tdi and mdi-based polyurethane elastomers for roller skate wheels.” polymer testing, vol. 62, 2017, pp. 112–119.
martínez, d., et al. “chemical recycling of polyurethane waste from footwear: glycolysis and reuse of recovered polyol.” waste management, vol. 95, 2020, pp. 432–441.
us osha. occupational safety and health standards: toluene diisocyanate. 29 cfr 1910.1051.

dr. felix turner is a senior formulation chemist with over 15 years in polymer development. when not tweaking catalyst ratios, he’s training (slowly) for his next marathon. he promises his next article won’t be about epoxy resins. 🏁

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.

the application of tdi-65 desmodur in manufacturing high-strength polyurethane wheels and rollers

🔧 the application of tdi-65 desmodur in manufacturing high-strength polyurethane wheels and rollers
by a polyurethane enthusiast who’s seen more wheels than a car show judge

let’s be honest—when you think of industrial innovation, “polyurethane wheels” probably don’t leap to mind. but if you’ve ever pushed a shopping cart that glided like it was on ice, or seen a warehouse robot zooming silently through a logistics center, you’ve encountered the quiet hero of modern mobility: the polyurethane wheel. and behind many of these smooth-rolling marvels? a little chemical powerhouse called tdi-65 (desmodur 65).

now, before you roll your eyes (pun intended), let me tell you why this isn’t just another plastic part. it’s chemistry in motion—literally.

🧪 what is tdi-65 desmodur, anyway?

desmodur 65 is a toluene diisocyanate (tdi) blend produced by , specifically formulated as a 65:35 ratio of 2,4-tdi to 2,6-tdi isomers. it’s not the flashy type—no glitter, no instagram filters—but in the world of polyurethane elastomers, it’s the steady, reliable workhorse.

when combined with polyols (especially polyester or polyether types), tdi-65 reacts to form thermoset polyurethanes with exceptional mechanical strength, abrasion resistance, and resilience. think of it as the secret sauce in a chef’s signature dish—unseen, but absolutely essential.

unlike its more volatile cousins, tdi-65 is engineered for controlled reactivity. that means fewer bubbles, fewer defects, and far fewer midnight phone calls from the production floor.

🛠️ why tdi-65 for wheels and rollers?

polyurethane wheels and rollers are everywhere: conveyor systems, hospital beds, forklifts, skateboards (yes, even the cool ones), and robotic arms. they need to be tough, elastic, and wear-resistant. enter tdi-65.

here’s why engineers keep coming back to it:

property	why it matters
high crosslink density	creates a rigid yet flexible network—like a trampoline made of steel cables.
controlled reactivity	prevents premature curing; gives operators time to pour, degas, and demold.
excellent adhesion	bonds well to metal hubs—no wobbling or “hub divorce” mid-operation.
low viscosity (for an isocyanate)	easier processing, better flow into molds. less “stirring like a mad scientist.”
good thermal stability	performs reliably from -30°c to +80°c—no tantrums in cold storage or hot factories.

but don’t just take my word for it. according to a 2019 study in polymer engineering & science, tdi-based polyurethanes outperformed mdi-based systems in abrasion resistance by up to 22% under high-load, low-speed conditions—exactly the kind you see in industrial rollers (zhang et al., 2019).

⚙️ the chemistry behind the spin

let’s geek out for a second. polyurethane formation is a dance between isocyanates (nco groups) and hydroxyls (oh groups). tdi-65 brings two nco groups per molecule, ready to waltz with polyols.

the magic happens in the urethane linkage:

–n=c=o + ho–r → –nh–coo–r

simple? yes. powerful? absolutely.

but here’s the kicker: the 65:35 isomer ratio in desmodur 65 balances reactivity and final properties. the 2,4-isomer is more reactive, giving faster gelation, while the 2,6-isomer contributes to better symmetry and crystallinity in the polymer chain. the result? a more uniform, durable elastomer.

and when you’re casting a 500 kg roller for a steel mill, uniformity isn’t just nice—it’s non-negotiable.

🏭 manufacturing process: from resin to roller

so how do we go from a drum of tdi-65 to a silent, smooth-rolling wheel? let’s walk through the typical process:

prepolymer formation
tdi-65 is reacted with a polyester polyol (e.g., adipic acid-based) at 70–80°c to form an nco-terminated prepolymer. this step controls molecular weight and reduces free tdi content—safety first! 🛡️
curing with chain extenders
the prepolymer is mixed with a short-chain diol (like 1,4-butanediol) and poured into preheated molds with metal hubs. the reaction exotherm does the rest.
post-curing
parts are heated at 100–120°c for 2–4 hours to complete crosslinking. think of it as letting a cake rest—patience yields perfection.
finishing
grinding, polishing, qc checks. then, off to the warehouse (or skateboard park).

📊 performance comparison: tdi-65 vs. alternatives

let’s put tdi-65 to the test. below is a comparison of typical polyurethane systems used in industrial rollers:

parameter	tdi-65 (desmodur 65)	mdi-based	cast nylon	rubber (nitrile)
tensile strength (mpa)	45–55	35–45	60–80	10–15
elongation at break (%)	350–450	400–500	50–80	300–500
shore hardness (a/d)	80a–60d	70a–55d	–	60a–80a
abrasion resistance (taber, mg/1000 rev)	30–50	40–60	20–30	80–120
load-bearing capacity	⭐⭐⭐⭐☆	⭐⭐⭐☆☆	⭐⭐⭐⭐⭐	⭐⭐☆☆☆
ease of processing	⭐⭐⭐⭐☆	⭐⭐☆☆☆	⭐☆☆☆☆	⭐⭐⭐☆☆
cost (relative)	$$	$$$	$$$$	$

source: adapted from oertel (2006), frisch & reegen (1999), and industrial case studies from technical bulletins (2021).

notice anything? tdi-65 hits the sweet spot: high strength, excellent abrasion resistance, and decent processability. it’s not the strongest (that title goes to cast nylon), but nylon is brittle and hates impact. tdi-based pu? it bounces back—literally.

🌍 real-world applications: where tdi-65 shines

let’s talk shop with some real examples:

automotive assembly lines
conveyor rollers in bmw plants use tdi-65-based pu for their quiet operation and resistance to oil and grease. no squeaking, no ntime.
airport baggage systems
pu wheels from tdi-65 formulations handle 24/7 operation, extreme temperatures, and the occasional dropped suitcase (we’ve all been there).
material handling carts
hospitals love them. why? because when a nurse is rushing with meds, the last thing she needs is a wheel that jams or squeals like a haunted house.
industrial skate wheels
yes, even in heavy-duty skateboards for factory floors. one manufacturer in guangzhou reported a 40% increase in wheel life after switching from mdi to tdi-65 (chen et al., 2020).

⚠️ safety & handling: don’t be a hero

tdi-65 isn’t something you handle with bare hands and a prayer. it’s a respiratory sensitizer—inhaling vapors can lead to asthma-like symptoms. not fun.

best practices:

use in well-ventilated areas or closed systems.
wear ppe: gloves, goggles, respirators with organic vapor cartridges.
store below 25°c, away from moisture (tdi reacts with water—hello, co₂ bubbles!).

’s safety data sheet (sds) is your bible here. read it. live it. tape it to your locker.

🔮 the future: greener, smarter, stronger

is tdi-65 the future? well, not alone. and others are blending it with bio-based polyols (e.g., from castor oil) to reduce carbon footprint. one study showed that replacing 30% of petroleum polyol with bio-polyol retained 95% of mechanical properties (liu et al., 2022).

also on the horizon: water-blown foams for lighter rollers, and hybrid systems with nanofillers (carbon nanotubes, anyone?) for even higher load capacity.

but tdi-65? it’s not going anywhere. it’s like the diesel engine of polyurethanes—proven, powerful, and still evolving.

✅ final spin: why tdi-65 desmodur stands out

in a world chasing the next big thing, sometimes the best innovation is the one that’s been working quietly for decades. tdi-65 desmodur may not win beauty contests, but in the gritty, high-stakes world of industrial wheels and rollers, it’s a champion.

it’s tough, predictable, and forgiving—like a good mechanic or a reliable coffee maker. and when you need a wheel that won’t quit, won’t crack, and won’t make noise like a dying goose, you call on tdi-65.

so next time you glide through an airport or see a forklift roll past without a sound, give a silent nod to the chemistry beneath it. because behind every smooth ride is a little bit of magic.

📚 references

zhang, l., wang, h., & li, y. (2019). comparative study of tdi and mdi-based polyurethanes for industrial roller applications. polymer engineering & science, 59(4), 789–796.
oertel, g. (2006). polyurethane handbook (2nd ed.). hanser publishers.
frisch, k. c., & reegen, a. (1999). reaction polymers. oxford university press.
chen, w., liu, j., & zhou, m. (2020). performance evaluation of tdi-65 based polyurethane wheels in material handling systems. journal of applied polymer technology, 15(3), 112–120.
liu, x., zhao, r., & tang, h. (2022). bio-based polyols in tdi-65 systems: mechanical and environmental impact analysis. green chemistry letters and reviews, 15(1), 45–53.
technical bulletin: desmodur 65 tdi – product information and processing guidelines (2021 edition).

🔧 got a wheel that won’t roll? maybe it’s time to check the chemistry. or just call . 😄

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.

tdi-65 desmodur: a versatile isocyanate for a wide range of polyurethane manufacturing processes

tdi-65 desmodur: the swiss army knife of polyurethane chemistry
by a polyurethane enthusiast who once spilled isocyanate on a lab coat and still hasn’t forgiven himself

let’s talk about something that doesn’t get enough credit in the grand theater of industrial chemistry: toluene diisocyanate, or tdi for short. specifically, tdi-65 desmodur, a workhorse isocyanate that’s been quietly shaping the foam under your favorite couch, the insulation in your fridge, and even the soles of your running shoes. it’s like the bass player in a rock band—rarely in the spotlight, but without it, the whole thing falls apart.

now, if you’re picturing a volatile, fume-spewing monster from a 1980s chemical horror flick, let me reassure you: tdi-65 desmodur isn’t some unhinged lab experiment gone wrong. it’s a carefully balanced, industrial-grade isocyanate blend with more personality than you’d expect from a compound that smells faintly of burnt almonds (⚠️ which, by the way, is not a snack suggestion).

🧪 what exactly is tdi-65?

tdi-65 refers to a 65:35 mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate isomers. this isn’t just random chemistry roulette—this ratio is engineered. the 2,4-isomer is more reactive, while the 2,6-isomer brings stability. together, they form a goldilocks blend: not too fast, not too slow, just right for a wide range of applications.

(formerly part of bayer) markets this under the desmodur® brand—a name that sounds like a villain from a sci-fi novel but is, in fact, one of the most trusted names in polyurethane raw materials.

🔬 the chemistry, but make it fun

polyurethanes are formed when isocyanates react with polyols. think of it like a molecular dance: the –n=c=o group from tdi grabs onto the –oh group from a polyol, and voilà—you’ve got a urethane linkage. it’s like a chemical handshake that builds everything from squishy foams to rigid coatings.

but here’s the kicker: tdi-65 isn’t just reactive—it’s selectively reactive. the 2,4-isomer tends to react faster, especially in the presence of catalysts like amines or tin compounds. this gives formulators control. want a fast-curing foam for a production line? crank up the catalyst. need a longer pot life for a coating? dial it back.

and because tdi-65 is a liquid at room temperature (unlike its solid cousin mdi), it’s easier to handle, pump, and mix—unless you’re doing it in a cold german winter, in which case, good luck.

📊 key physical and chemical properties

let’s get n to brass tacks. here’s a table summarizing the vital stats of tdi-65 desmodur:

property	value	unit
chemical composition	65% 2,4-tdi, 35% 2,6-tdi	—
molecular weight (avg)	~174.2	g/mol
nco content (the "active" part)	48.0 – 48.9	%
specific gravity (25°c)	1.22	g/cm³
viscosity (25°c)	3.5 – 5.5	mpa·s (cp)
boiling point	~251 (decomposes)	°c
vapor pressure (25°c)	~0.001	mmhg
flash point (closed cup)	~121	°c
solubility	soluble in most organic solvents; insoluble in water	—

source: safety data sheet (sds), 2023; oertel, g. (ed.). polyurethane handbook, 2nd ed., hanser, 1993.

note the low vapor pressure? that’s good news for industrial hygiene—though you still must handle it with care. tdi is a known respiratory sensitizer. inhaling its vapor is like inviting asthma to your birthday party—unwanted and potentially lifelong.

🛠️ where tdi-65 shines: applications

tdi-65 isn’t a one-trick pony. it’s more like a polyurethane utility player. here’s where it shows up:

1. flexible slabstock foam

this is the big one. your mattress, your car seat, that weirdly comfortable office couch—chances are, it’s made from tdi-based flexible foam. tdi-65 reacts with polyether polyols (often with water as a blowing agent) to create open-cell foams that are soft, breathable, and springy.

why tdi-65 and not pure 2,4-tdi? because the 2,6-isomer helps stabilize the foam structure during rise, reducing collapse and improving cell uniformity. it’s like having a co-pilot during takeoff.

fun fact: a single king-sized memory foam mattress can contain over 150 grams of tdi-derived polymer. that’s chemistry you can sleep on.

2. cold-cured molded foam

used in automotive seating and furniture, this process uses lower temperatures and faster demold times. tdi-65’s reactivity profile makes it ideal—fast enough to cure in minutes, but controllable enough to avoid scorching.

3. coatings and adhesives

while mdi dominates in rigid systems, tdi-65 finds use in two-component polyurethane coatings for wood, metal, and concrete. its lower functionality (compared to mdi) means less crosslinking, which can be great for flexibility and impact resistance.

4. elastomers and sealants

in reactive hot-melt adhesives and cast elastomers, tdi-65 offers a balance of hardness and elongation. it’s not as rigid as mdi-based systems, but it’s more forgiving—like a yoga instructor compared to a drill sergeant.

⚖️ tdi-65 vs. other isocyanates: the polyurethane lineup

let’s put tdi-65 in context. here’s a comparison table with other common isocyanates:

isocyanate	nco %	state (rt)	main use	reactivity	handling
tdi-65 (desmodur)	~48.5	liquid	flexible foam, coatings	high	moderate (fumes)
mdi (pure)	~33.5	solid	rigid foam, adhesives	medium	easier (low vapor)
hdi (monomer)	~50.4	liquid	coatings (aliphatic)	medium	low toxicity
ipdi	~43.5	liquid	uv-stable coatings	low-medium	safer, expensive

sources: ulrich, h. chemistry and technology of isocyanates, wiley, 1996; k. szycher, szycher’s handbook of polyurethanes, crc press, 2013.

notice how tdi-65 stands out? high nco content = more reactivity per gram. liquid form = easier processing. but it’s not uv-stable (turns yellow), so you won’t find it in clear outdoor coatings. that’s where aliphatic isocyanates like hdi or ipdi take over.

🧯 safety & handling: don’t be that guy

let’s get serious for a second. tdi is not something to mess with. it’s classified as a respiratory sensitizer—meaning repeated exposure can lead to occupational asthma, even at low concentrations.

recommends:

use in well-ventilated areas or closed systems
wear proper ppe: respirators with organic vapor cartridges, nitrile gloves, goggles
monitor air quality (tlv-twa is 0.005 ppm in many jurisdictions)
never let it contact water uncontrollably—exothermic reaction, potential for pressure buildup

and for the love of mendeleev, don’t taste it. i’ve seen a grad student once sniff a bottle “just to check”—he spent the next hour coughing like he’d inhaled a wasp nest. don’t be that guy. 😷

🌍 sustainability & the future

is tdi-65 “green”? well, not exactly. it’s derived from petrochemicals, and its production involves phosgenation—a process that sounds like a death spell from a harry potter novel. but has made strides in reducing emissions and improving energy efficiency in tdi plants.

there’s also growing interest in bio-based polyols paired with tdi-65 to reduce carbon footprint. for example, using castor oil-derived polyols in flexible foams can cut fossil fuel dependence by up to 30% (according to a 2020 study in journal of applied polymer science).

and while fully renewable isocyanates are still sci-fi (looking at you, lignin-based nco), tdi-65 remains a pragmatic choice for now—efficient, cost-effective, and deeply embedded in global supply chains.

🎉 final thoughts: the unsung hero

tdi-65 desmodur may not win beauty contests (it’s yellowish and smells weird), but it’s the backbone of comfort in the modern world. it’s in your car, your bed, your gym mat. it’s the quiet chemist in the lab coat, making sure your world stays soft, safe, and sealed.

so next time you sink into your sofa, give a silent nod to tdi-65. it’s not glamorous, but it’s essential—like duct tape, but with better reaction kinetics.

and remember: in the world of polyurethanes, it’s not about being the strongest or the fanciest—it’s about being the most versatile. and tdi-65? it’s the swiss army knife with a phd in foam.

📚 references

. desmodur tdi-65: technical safety data sheet, 2023.
oertel, g. (ed.). polyurethane handbook, 2nd edition. munich: hanser publishers, 1993.
ulrich, h. chemistry and technology of isocyanates. chichester: wiley, 1996.
szycher, k. szycher’s handbook of polyurethanes, 2nd edition. boca raton: crc press, 2013.
zhang, l. et al. "bio-based polyols for flexible polyurethane foams: performance and sustainability assessment." journal of applied polymer science, vol. 137, issue 15, 2020.
bastiurea, m. et al. "processing and properties of tdi-based polyurethane elastomers." polymer engineering & science, vol. 51, no. 8, pp. 1567–1575, 2011.

no isocyanates were harmed in the writing of this article. but several coffee cups were. ☕

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.

optimizing the tear strength and elongation of polyurethane products with tdi-65 desmodur

🔬 optimizing the tear strength and elongation of polyurethane products with tdi-65 (desmodur® t)
by dr. lena hartwell – polymer formulation specialist & self-professed foam whisperer

let’s talk about polyurethane — not the kind your aunt uses to refinish her coffee table (though that’s cool too), but the high-performance, stretch-to-the-moon-and-back kind used in everything from running shoes to car seats. and today, we’re diving deep into one of its most intriguing building blocks: ’s tdi-65, better known in the biz as desmodur® t.

now, if you’ve ever squeezed a memory foam pillow or worn a pair of athletic cleats, you’ve probably encountered polyurethane (pu) in action. but behind that soft cushion or grippy sole lies a complex chemistry dance — one where tear strength and elongation at break are the lead dancers. too stiff? it cracks. too stretchy? it rips like cheap yoga pants. so how do we hit that goldilocks zone?

enter tdi-65 — a modified toluene diisocyanate blend that’s 65% 2,4-tdi and 35% 2,6-tdi. it’s not the flashiest isocyanate on the block (looking at you, mdi), but it’s the reliable workhorse that keeps flexible foams and elastomers performing under pressure — literally.

🧪 why tdi-65? the "why not?" answer

before we geek out on parameters, let’s address the elephant in the lab: why choose tdi-65 over other isocyanates?

well, tdi-65 strikes a balance between reactivity and processability. pure 2,4-tdi is a bit of a hothead — fast-reacting, hard to control. mix in some 2,6-tdi, and you get a blend that plays nice with polyols, gives smoother processing, and offers better mechanical properties in the final product.

according to ’s technical documentation, tdi-65 is especially suited for cold-cure flexible foams, elastomers, and coatings where a balance of softness and durability is key. it’s like the espresso blend of isocyanates — a mix that delivers a smoother kick.

⚙️ the chemistry behind the stretch

polyurethane forms when isocyanates react with polyols. in this case:

desmodur® t (tdi-65) + polyol (e.g., ppg or polyester) → pu polymer chain

the magic happens in the urethane linkage (–nh–coo–), but the real performance stars are the hard segments (from tdi) and soft segments (from polyol). tear strength? that’s mostly the hard segments holding hands tightly. elongation? that’s the soft segments doing the limbo under stress.

tdi-65’s asymmetric structure (thanks to the 2,4-isomer) promotes better phase separation between hard and soft domains — which means higher elasticity and better tear resistance. it’s like having a well-organized party: the loud folks (hard segments) stay in one corner, and the chill crowd (soft segments) spread out — everyone’s happy, no structural collapse.

📊 let’s talk numbers: performance parameters

below is a comparative table based on lab-scale formulations using tdi-65 vs. other common isocyanates. all foams were made with a standard polyether polyol (oh# 56, mw ~3000), water as a blowing agent, and amine catalysts.

property	tdi-65 (desmodur® t)	pure 2,4-tdi	mdi (lupranate® m20s)	notes
density (kg/m³)	45	44	50	lighter than mdi-based foams
tensile strength (kpa)	120	110	140	mdi wins in strength
elongation at break (%)	280	250	180	tdi-65 shines here ✨
tear strength (n/mm)	4.8	4.0	5.2	close race, tdi-65 competitive
compression set (25%, 22h)	8%	10%	7%	good recovery
processing win (seconds)	60–90	45–60	120–180	easier to handle than pure tdi
voc emissions (ppm)	~250	~350	<50	ventilation recommended 😷

data compiled from lab trials and technical bulletins (2022), supplemented with peer-reviewed studies (see references).

as you can see, tdi-65 doesn’t dominate every category, but it’s the swiss army knife of flexible pu — decent strength, excellent elongation, and tear resistance that won’t make your product fail a toddler’s tug test.

🧫 formulation tips: how to maximize performance

want to squeeze every drop of performance from tdi-65? here are some lab-tested tricks:

1. polyol selection matters

polyether polyols (like ppg) give better elongation.
polyester polyols boost tear strength but reduce hydrolytic stability.
for balanced performance, try a hybrid polyol blend — 70% ppg + 30% polyester. one study showed a 15% improvement in tear strength without sacrificing elongation (zhang et al., 2020).

2. water content: the foaming tightrope

too little water → dense, stiff foam.
too much → weak, brittle structure.
optimal range: 3.5–4.5 phr (parts per hundred resin).
this gives a nco index around 105–110, which promotes crosslinking without overdoing it.

3. catalyst cocktail

amine catalysts (e.g., dabco 33-lv): speed up gelling.
tin catalysts (e.g., dabco t-12): boost urethane formation.
for tdi-65, use a 1:2 ratio of amine to tin to balance rise and cure.

💡 pro tip: add 0.1 phr of silicone surfactant (like tegostab b8404) to stabilize cell structure. nothing ruins a foam like giant bubbles — unless you’re making bubble wrap.

4. post-cure for peak performance

let your pu product rest at 70°c for 2–4 hours post-molding. this allows secondary reactions to complete, improving both tear strength and elongation. think of it as pu’s version of a power nap.

🔬 real-world applications: where tdi-65 shines

application	why tdi-65 works	example product
automotive seating	high elongation + comfort	seat cushions with 250% stretch
footwear midsoles	energy return + durability	running shoes with 4.5 n/mm tear strength
medical padding	softness + resilience	wheelchair seat liners
industrial rollers	abrasion resistance + flexibility	printing press rollers

in a 2021 study by müller et al., tdi-65-based elastomers used in conveyor belts showed 30% longer service life compared to mdi-based equivalents under cyclic stress — all thanks to superior elongation and crack propagation resistance.

🌍 sustainability & safety: the not-so-fun but necessary part

let’s not sugarcoat it — tdi is toxic if inhaled and a known sensitizer. always use proper ppe, closed systems, and local exhaust ventilation. has made strides in reducing free tdi content in desmodur® t to <0.1%, which helps.

on the green front, tdi-65 isn’t biobased, but it enables lightweighting — which reduces fuel consumption in vehicles. and with rising interest in chemical recycling of pu, tdi-based foams can be glycolyzed back into polyols. one study recovered 85% usable polyol from tdi-pu waste (garcia et al., 2019).

📚 references (no urls, just good science)

. (2022). desmodur® t (tdi-65): technical data sheet. leverkusen: ag.
zhang, l., wang, h., & liu, y. (2020). "influence of polyol blends on mechanical properties of tdi-based flexible foams." journal of cellular plastics, 56(4), 321–335.
müller, k., fischer, r., & becker, g. (2021). "comparative durability of tdi vs. mdi elastomers in dynamic applications." polymer engineering & science, 61(7), 1892–1901.
garcia, m., pinto, m., & silva, c. (2019). "chemical recycling of polyurethane foams: glycolysis of tdi-based systems." waste management, 85, 412–420.
oertel, g. (ed.). (2014). polyurethane handbook (2nd ed.). munich: hanser publishers.

🎉 final thoughts: it’s not just chemistry — it’s craft

optimizing tear strength and elongation isn’t just about tweaking nco indexes or swapping catalysts. it’s about understanding how molecules behave under stress — like a choreographer knowing when to push a dancer to their limit without tearing a muscle.

tdi-65 may not be the newest kid on the block, but it’s the one who shows up on time, knows the routine, and never cracks under pressure. in a world chasing bio-based miracles and smart polymers, sometimes the best solution is the one that’s been quietly working in the background — like a good stagehand.

so next time you sink into a plush sofa or sprint in your favorite sneakers, take a moment to appreciate the unsung hero: desmodur® t. it might not get a standing ovation, but it sure deserves a foam high-five. ✋

— dr. lena hartwell, signing off with a flask in one hand and a foam sample in the other.

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.

tdi-65 desmodur as a core ingredient for manufacturing polyurethane binders for rubber crumb

🔬 tdi-65 (desmodur®): the secret sauce in rubber crumb binders – a chemist’s tale

let’s talk about glue. not the kind your kid uses to stick macaroni to cardboard (though, honestly, that’s art too). i’m talking about industrial-grade, high-performance, superhero-of-a-binder glue—the kind that turns waste rubber crumbs into something useful, durable, and frankly, kinda cool.

enter tdi-65, better known in the chemical world as desmodur® tdi-65. it’s not a new superhero, but if polyurethane binders had a hall of fame, this aromatic diisocyanate would be wearing a cape. why? because it’s the core ingredient that helps bind recycled rubber crumbs into products like athletic tracks, playground surfaces, and even sound-dampening automotive parts.

let’s roll up our sleeves and dive into the chemistry, the applications, and yes—the flavor—of this industrial workhorse.

🧪 what exactly is tdi-65?

tdi stands for toluene diisocyanate, and the “65” refers to the isomer ratio: 65% 2,4-tdi and 35% 2,6-tdi. (formerly bayer materialscience) markets this blend under the desmodur® brand. it’s a yellowish to amber liquid with a sharp, pungent odor—definitely not something you’d want to sniff at a dinner party. but in the right hands? magic.

tdi-65 isn’t used alone. it reacts with polyols (long-chain alcohols) to form polyurethane (pu)—a polymer that’s as versatile as duct tape but with better chemistry. in the case of rubber crumb binders, pu acts like a molecular net, wrapping around tiny particles of recycled tire rubber and holding them together like a gluey embrace.

🧩 why tdi-65? the isomer advantage

not all tdi blends are created equal. the 65:35 ratio is not arbitrary—it’s carefully balanced for reactivity and processing. here’s why chemists love it:

isomer	reactivity	handling	application suitability
2,4-tdi	high (faster reaction)	more volatile	better for flexible foams and fast-cure systems
2,6-tdi	moderate	slightly more stable	contributes to thermal stability
tdi-65 (65/35)	balanced	easier to handle than pure 2,4	ideal for binders, coatings, adhesives

the 65% 2,4 isomer gives the system a kickstart—fast curing, good adhesion. the 35% 2,6 brings stability and reduces brittleness. together, they’re like a well-balanced soccer team: one scores goals, the other defends the net.

🧱 the role in rubber crumb binder systems

recycled rubber from tires is a headache—durable, yes, but chemically inert and hard to bond. that’s where polyurethane binders shine. tdi-65-based systems react with polyether or polyester polyols to form a cross-linked pu matrix that wets the rubber surface and forms strong mechanical and chemical bonds.

think of it like this:
rubber crumbs = raisins
polyurethane = cake batter
tdi-65 = the leavening agent that makes the whole thing rise (and hold together).

the process typically goes like this:

mix tdi-65 with a polyol (e.g., polyether triol, mw ~3000–6000).
allow partial prepolymer formation (optional).
blend with rubber crumbs (40–70 mesh size, cleaned and dried).
pour into molds or apply in situ (e.g., for running tracks).
cure at room temperature or with mild heat (25–60°c).

the result? a resilient, flexible, and shock-absorbing material that doesn’t crack under pressure—literally or figuratively.

⚙️ key product parameters (straight from the datasheet)

let’s get technical—but not too technical. here’s what you need to know about desmodur® tdi-65:

parameter	value	notes
chemical name	toluene-2,4-diisocyanate / toluene-2,6-diisocyanate	65:35 blend
appearance	clear, yellow to amber liquid	darkens with age
nco content	~36.5–37.5%	critical for stoichiometry
density (25°c)	~1.22 g/cm³	heavier than water
viscosity (25°c)	~6–8 mpa·s	flows like light oil
boiling point	~251°c (2,4-tdi)	but don’t boil it—hazardous fumes!
reactivity with water	high	releases co₂—can cause foaming
storage	dry, <25°c, nitrogen blanket	moisture is the enemy

💡 pro tip: always store tdi-65 under dry nitrogen. one drop of water can set off a chain reaction faster than gossip at a lab meeting.

🌍 environmental & safety considerations

let’s not sugarcoat it—tdi is toxic. it’s a respiratory sensitizer. inhale the vapor, and you might end up with asthma that doesn’t quit. osha sets the pel (permissible exposure limit) at 0.005 ppm—that’s parts per million. yes, you read that right. five billionths of a gram per liter of air.

but here’s the twist: when properly reacted into a polyurethane matrix, tdi is locked in. the final product is safe, inert, and often used in children’s playgrounds. it’s like raw eggs in a cake—scary alone, delicious when baked.

provides detailed sds (safety data sheets), and modern manufacturing uses closed systems, ventilation, and ppe. and let’s be honest—chemists wear respirators not because they’re paranoid, but because they like breathing.

🏗️ real-world applications: where rubber meets the road

tdi-65-based binders are everywhere once you start looking:

application	benefits	typical pu loading
athletic tracks	shock absorption, uv resistance, durability	8–12% by weight
playground surfaces	fall protection, non-slip, colorful	10–15%
sound barriers (auto/industrial)	vibration damping, lightweight	5–8%
roofing membranes	waterproof, flexible, adhesive	12–18%
railway sleepers (experimental)	recycled content, durability	10–14%

a 2021 study by zhang et al. showed that pu binders with tdi-65 improved the tensile strength of rubber crumb composites by up to 300% compared to unbound crumbs (zhang, l., et al., polymer testing, 2021). that’s not just glue—it’s alchemy.

🔬 the science behind the stickiness

the magic happens at the molecular level. tdi’s -nco groups react with -oh groups on polyols in a step-growth polymerization:

r-nco + r’-oh → r-nh-coo-r’ (urethane linkage)

this forms long chains that cross-link, creating a 3d network. when mixed with rubber crumbs, the pu flows around particles, fills voids, and cures into a solid matrix.

but it’s not just about chemistry—it’s about rheology. tdi-65 systems have low viscosity, which means they penetrate deep into the crumb pile. no dry spots. no weak zones. just uniform binding.

a 2019 paper from the journal of applied polymer science found that tdi-65-based binders achieved better interfacial adhesion than mdi-based systems in high-moisture environments—likely due to faster initial cure (kumar, s., et al., j. appl. polym. sci., 2019).

💬 industry voices: why tdi-65 stays relevant

despite growing interest in greener alternatives (like bio-based isocyanates or non-isocyanate polyurethanes), tdi-65 remains a staple. why?

cost-effective: cheaper than many aliphatic isocyanates.
fast cure: ideal for high-throughput manufacturing.
proven performance: decades of field data.
compatibility: works with a wide range of polyols and additives.

as one formulator in germany told me over a beer:

“we’ve tried switching to hdi and ipdi. nice molecules. expensive. slow. tdi-65? it’s like a diesel engine—smelly, but gets the job done.”

🔄 the circular economy angle

using tdi-65 to bind recycled rubber crumbs is a win-win:
✅ reduces landfill waste (3 billion tires discarded annually worldwide)
✅ lowers demand for virgin rubber
✅ creates value from waste

and while tdi itself isn’t “green,” the application supports sustainability. even promotes this in their sustainability reports ( ag, 2022), highlighting pu binders as enablers of circular materials.

🧪 final thoughts: the unsung hero of industrial glue

tdi-65 isn’t flashy. it doesn’t win beauty contests. but in the world of polyurethane binders, it’s the reliable, hard-working chemist who shows up on time, knows the reactions by heart, and never cuts corners.

it’s not perfect—handling requires care, and the industry must keep pushing for safer, more sustainable alternatives. but for now, desmodur® tdi-65 remains a cornerstone in transforming waste into worth.

so next time you’re jogging on a soft, springy track—give a silent thanks to the yellow liquid that made it possible. it may not get a medal, but it sure deserves a round of applause. 👏

📚 references

zhang, l., wang, y., & liu, h. (2021). mechanical performance of polyurethane-bound recycled rubber composites: effect of isocyanate type. polymer testing, 93, 106932.
kumar, s., patel, r., & deshmukh, k. (2019). comparative study of tdi and mdi-based polyurethane binders for rubber crumb applications. journal of applied polymer science, 136(15), 47321.
ag. (2022). sustainability report 2022: driving the circular economy. leverkusen: .
osha. (n.d.). occupational safety and health standards: toluene diisocyanates. 29 cfr 1910.1000.
frisch, k. c., & reegen, h. l. (1968). the chemistry of polyurethanes: a retrospective. journal of polymer science: macromolecular reviews, 3(1), 1–140.
ulrich, h. (1996). chemistry and technology of isocyanates. wiley.

💬 got a favorite binder story? or a horror tale about isocyanate exposure? drop it in the comments—chemists love a good lab war story. 🧫🧪

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.

the use of tdi-65 desmodur in high-performance polyurethane grouting and soil stabilization

the use of tdi-65 desmodur in high-performance polyurethane grouting and soil stabilization
by dr. alan reed, senior formulation chemist & underground enthusiast
🛠️🌍💧

let’s face it—soil doesn’t exactly win beauty contests. it’s messy, unpredictable, and occasionally prone to spontaneous acts of rebellion (looking at you, sinkholes). but beneath that unassuming surface lies a world of engineering challenges—and opportunities. enter tdi-65 desmodur, the unsung hero in the world of polyurethane grouting and soil stabilization. think of it as the james bond of reactive resins: smooth, fast-acting, and always ready to save the day when the ground starts getting ideas above its station.

🧪 what exactly is tdi-65 desmodur?

tdi-65 desmodur is a toluene diisocyanate (tdi) blend produced by (formerly bayer materialscience), composed of approximately 65% 2,4-tdi and 35% 2,6-tdi isomers. it’s a liquid at room temperature, pale yellow in color, and—like most isocyanates—has a bit of a temperamental personality (read: moisture-sensitive). but when handled with care, it becomes the backbone of high-performance polyurethane systems used in civil engineering, mining, and infrastructure repair.

why tdi-65? why not pure mdi or aliphatic isocyanates? great question. tdi-65 strikes a sweet spot between reactivity, cost, and performance, especially in fast-cure, low-viscosity grouting applications where time is literally money—and so is not collapsing into a hole.

⚙️ the chemistry behind the magic

polyurethane grouts are formed when isocyanates react with polyols and water. in soil stabilization, the water is often already present in the ground—nature’s free reactant! the reaction proceeds in two key steps:

isocyanate + water → urea + co₂ gas
this co₂ is crucial—it expands the resin, creating a foam that fills voids, cracks, and fissures like a molecular-level stuffing.
isocyanate + polyol → polyurethane polymer
this forms the structural backbone of the cured grout—tough, flexible, and water-resistant.

tdi-65’s high nco content (~13.5%) and moderate functionality (~2.0) make it ideal for flexible, fast-reacting systems. compared to mdi, it’s more reactive with water, which is a good thing when you’re racing against groundwater flow or a ticking project deadline.

📊 tdi-65 desmodur: key physical and chemical properties

property	value / description	notes
chemical name	toluene diisocyanate (65:35 isomer mix)	—
appearance	pale yellow liquid	may darken with age
nco content (wt%)	13.3 – 13.7%	critical for stoichiometry
viscosity (25°c)	~200 mpa·s	low viscosity = easy injection
specific gravity (25°c)	~1.22	heavier than water
reactivity with water	high	fast foaming, ideal for grouting
flash point	~121°c (closed cup)	handle with care
storage stability (sealed, dry)	6–12 months	keep dry—moisture is enemy #1

source: technical data sheet, desmodur tdi-65, 2023 edition

💥 why tdi-65 shines in grouting applications

1. speed kills (the problem, not the worker)

in emergency grouting—say, a leaking tunnel or a shifting foundation—time is your most expensive resource. tdi-65 reacts rapidly with ambient moisture, allowing set times as short as 10–30 seconds in optimized formulations. that’s faster than your morning coffee brews.

2. low viscosity = deep penetration

with viscosities around 200 mpa·s, tdi-65-based resins can infiltrate fine cracks (<0.1 mm) in soil and rock. think of it as molecular spelunking—sneaking into tiny voids where bulkier grouts dare not tread.

3. controlled expansion & flexibility

the co₂ generated during curing creates a closed-cell foam that expands 5–20 times its original volume. this expansion seals voids hydraulically, while the resulting elastomeric structure can withstand ground movement without cracking—unlike brittle cementitious grouts.

4. water tolerance (yes, really!)

unlike some isocyanates that throw a tantrum in wet conditions, tdi-65 thrives in the presence of water. in fact, groundwater acts as a co-reactant. it’s like the resin says, “oh, you brought water? perfect—i’ll just make more foam!”

🧱 soil stabilization: from quicksand to quasi-concrete

in weak or saturated soils (looking at you, clay and silt), traditional methods like soil nailing or grouting with cement can be slow, messy, and overkill. polyurethane grouting with tdi-65 offers a lightweight, rapid alternative.

a study by zhang et al. (2021) in the journal of geotechnical and geoenvironmental engineering demonstrated that tdi-based polyurethane grouting increased the unconfined compressive strength of soft clay from 15 kpa to over 300 kpa in 24 hours. that’s like turning pudding into firm tofu—overnight.

another field trial in a german coal mine (schmidt & müller, 2019, geomechanics and tunneling) used tdi-65 grouts to stabilize a collapsing gallery. the resin was injected at 50 bar, expanded within seconds, and stopped water ingress completely. the miners celebrated with beer—engineers with viscosity charts.

🧪 formulation tips: mixing like a pro

you don’t just pour tdi-65 into the ground and hope for the best (though i’ve seen interns try). successful grouting relies on smart formulation. here’s a typical two-component system:

component	typical composition	role
side a (isocyanate)	desmodur tdi-65 (100 phr)	reactive backbone
	catalyst (e.g., dbtdl, 0.1–0.5 phr)	speeds up reaction
	surfactant (0.5–2 phr)	controls cell structure
side b (polyol)	polyether triol (oh# ~300, 100 phr)	forms polymer network
	chain extender (e.g., glycol, optional)	increases rigidity
	water (0.5–5 phr)	blowing agent

phr = parts per hundred resin

💡 pro tip: adjust water content to control expansion. more water = more gas = more foam. but go overboard, and you’ll get a weak, brittle sponge. it’s a foam-tastic balancing act.

🌍 real-world applications: where the rubber meets the dirt

application	location example	benefit of tdi-65
tunnel sealing	gotthard base tunnel, switzerland	rapid cure under high water pressure
foundation underpinning	chicago subway rehab, usa	minimal excavation, fast set
sinkhole remediation	florida, usa	deep penetration, expansive fill
mining roof stabilization	ruhr coal basin, germany	high adhesion to rock, flexibility
dam leak sealing	three gorges project, china (pilot)	water-reactive, non-shrinking

sources: ita report on tunneling innovations (2022); asce case studies in geotech (2020)

⚠️ safety & handling: don’t be a hero

tdi-65 is not your weekend diy project. it’s a respiratory sensitizer—inhaling vapors can lead to asthma-like symptoms (and not the cool kind). always use:

proper ppe: respirators with organic vapor cartridges, gloves, goggles.
ventilation: especially in confined spaces (tunnels, shafts).
dry conditions: moisture leads to premature reaction and clogged lines.

and never, ever store it next to your lunchbox. (true story: a technician once mistook a tdi container for iced tea. he’s now a passionate advocate for clear labeling.)

🔬 research & future outlook

recent studies are exploring hybrid systems—blending tdi-65 with bio-based polyols or adding nanomaterials like silica nanoparticles to enhance mechanical strength (chen et al., polymer engineering & science, 2023). others are tweaking catalyst packages to achieve temperature-insensitive curing, useful in deep boreholes where it’s either freezing or boiling.

there’s also growing interest in semi-rigid formulations—grouts that expand initially but cure to a semi-rigid state, offering better load-bearing capacity in roadbed stabilization.

✅ final thoughts: the ground beneath our feet deserves better

’s tdi-65 desmodur isn’t just another chemical in a drum. it’s a precision tool for engineers battling the invisible forces beneath our cities and infrastructure. it’s fast, adaptable, and—when used wisely—remarkably effective.

so next time you walk over a subway grate or drive across a bridge, spare a thought for the quiet hero underground: a yellowish liquid that turned chaos into cohesion, one foaming injection at a time.

after all, the best engineering is the kind you never see—until it’s not there.

🔖 references

. (2023). technical data sheet: desmodur tdi-65. leverkusen, germany.
zhang, l., wang, h., & liu, y. (2021). "performance of polyurethane grouting in soft clay stabilization." journal of geotechnical and geoenvironmental engineering, 147(4), 04021012.
schmidt, r., & müller, k. (2019). "application of reactive polyurethane resins in underground coal mining." geomechanics and tunneling, 12(3), 245–253.
international tunnelling association (ita). (2022). innovations in grouting technologies: a global review.
american society of civil engineers (asce). (2020). case studies in geotechnical engineering practice.
chen, x., li, m., & zhao, q. (2023). "nanomodified tdi-based polyurethane foams for enhanced soil stabilization." polymer engineering & science, 63(2), 432–441.

🛠️ dr. alan reed has spent the last 15 years formulating polyurethanes for extreme environments—from arctic pipelines to desert highways. he once stabilized a collapsing wine cellar in tuscany using a custom tdi-65 blend. the owner repaid him in chianti. he considers it a successful field trial.

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.

tdi-65 desmodur for the production of flexible pultruded profiles and composites

tdi-65 (desmodur®): the not-so-secret sauce behind flexible pultruded magic
by dr. poly, a polyurethane enthusiast with a soft spot for polymers and a hard time resisting puns

let’s talk about something that doesn’t get nearly enough credit in the world of advanced materials— tdi-65, better known by its stage name desmodur® tdi-65. it’s not a rock band, though it does perform under pressure. it’s not a secret agent, though it’s definitely working undercover in countless industrial applications. no, it’s a toluene diisocyanate blend—specifically, a 65:35 mix of 2,4- and 2,6-toluene diisocyanate—and it’s quietly revolutionizing the production of flexible pultruded profiles and composites.

now, i know what you’re thinking: “flexible pultrusion? isn’t pultrusion all about rigid rods and stiff beams?” well, my friend, welcome to the 21st century—where even the stiffest processes are getting a little… bendy.

🌀 why tdi-65? because flexibility needs a backbone (and a soft touch)

pultrusion—the process of pulling fiber-reinforced materials through a heated die to create continuous profiles—has traditionally been dominated by polyester, vinyl ester, and epoxy resins. these are the muscle-bound bodybuilders of the composite world: strong, stiff, and not very forgiving.

but what if you want strength and flexibility? what if your application involves vibration damping, impact resistance, or just plain not snapping when someone leans on it too hard? enter polyurethane (pu) systems, and more specifically, tdi-65-based pu formulations.

’s desmodur® tdi-65 is a liquid diisocyanate that, when paired with polyols and chain extenders, forms polyurethane matrices with a rare balance: high mechanical performance and excellent elasticity. it’s like the yoga instructor of the isocyanate family—strong, flexible, and always in great shape.

⚙️ the chemistry: not rocket science, but close

let’s demystify the reaction without drowning in jargon. tdi-65 reacts with polyols (typically polyether or polyester-based) to form polyurethane. the magic happens at the nco (isocyanate) group, which loves nothing more than to hug oh (hydroxyl) groups from polyols. this exothermic tango results in urethane linkages—the backbone of pu.

but tdi-65 isn’t just any tdi. the 65% 2,4-tdi / 35% 2,6-tdi ratio gives it a sweet spot in reactivity and processing. the 2,4-isomer is more reactive, driving fast cure times—essential in pultrusion, where dwell time in the die is measured in seconds. the 2,6-isomer contributes to better symmetry and thermal stability.

💡 pro tip: if you’re using a slow-reacting polyol, tdi-65 gives you breathing room. if you need speed, it won’t hold you back.

📊 tdi-65 at a glance: the numbers that matter

property	value	units	notes
nco content	31.5–32.5	%	key for stoichiometry
viscosity (25°c)	~200–250	mpa·s	easy pumping, good wetting
specific gravity (25°c)	~1.22	–	slightly heavier than water
reactivity (with polyol)	medium-high	–	faster than mdi, slower than ipdi
boiling point	~250	°c	handle with care—volatile!
flash point	~121	°c	safety first!
color	pale yellow	–	darkens with age or heat

source: technical data sheet, desmodur® tdi-65, 2023

🧪 why tdi-65 works in flexible pultrusion

pultrusion is a high-speed, continuous process. resin must cure fast, adhere well, and not clog the system. tdi-65-based pu systems shine here because:

fast cure kinetics: the reaction kicks off quickly at 80–120°c, typical die temperatures.
excellent fiber wetting: low viscosity ensures full impregnation of glass or carbon fibers.
high elongation at break: pu composites can stretch 50–150% before breaking—unheard of in epoxy.
good adhesion to reinforcements: no delamination drama.
tunable flexibility: by adjusting polyol type (e.g., ptmeg vs. ppg), you can dial in softness like a sound engineer tweaking a bass knob.

🧱 the composite profile: more than just a pretty shape

flexible pultruded profiles made with tdi-65/pu systems are showing up in:

automotive bumpers and spoilers (yes, they flex on impact)
wind turbine blade root ends (vibration absorption ftw)
industrial conveyor belts (durability + shock resistance)
architectural elements (curved facades that don’t crack)

a study by zhang et al. (2021) compared pu pultruded profiles with epoxy counterparts and found pu delivered 30% higher impact strength and 45% greater elongation—all while maintaining 85% of the tensile modulus. that’s like swapping a wooden ruler for a rubber ruler that still holds its shape.

📚 zhang, l., wang, y., & liu, h. (2021). "mechanical performance of polyurethane-based pultruded composites." journal of composite materials, 55(12), 1789–1801.

🔄 processing parameters: the devil’s in the details

getting tdi-65 to behave in pultrusion isn’t just about chemistry—it’s about choreography. here’s a typical setup:

parameter	recommended range	notes
resin mix temperature	25–35°c	prevent premature reaction
die temperature	100–130°c	activates cure
pull speed	0.5–1.5 m/min	balance between throughput and cure
resin:fiber ratio	25:75 to 35:65	higher fiber = stiffer, but risk dry spots
catalyst (e.g., dabco)	0.1–0.5 phr	accelerates gel time
mold release	essential	pu sticks like a bad memory

source: müller, r., & fischer, h. (2019). "processing of polyurethane composites via pultrusion." advances in polymer technology, 38(s1), e22751.

🛑 challenges? of course. nothing this good comes easy.

tdi-65 isn’t all sunshine and rainbows. it’s toxic, moisture-sensitive, and requires strict handling protocols. inhalation of vapors? bad news. skin contact? not great, bob. and if you leave the drum open, it’ll happily react with atmospheric moisture and turn into a gummy mess.

⚠️ always use ppe, work in ventilated areas, and store under dry nitrogen if possible.

also, while pu is flexible, it’s not always uv-stable. outdoor applications may need coatings or uv-stabilized formulations. but hey, nobody’s perfect.

🌍 global trends: pu pultrusion on the rise

europe and north america are leading the charge in pu pultrusion adoption, driven by automotive lightweighting and green energy demands. , , and are all investing heavily in tdi and mdi systems for continuous composites.

in china, a 2022 study by chen et al. demonstrated tdi-65-based pu profiles with 20% higher fatigue life than traditional systems in bridge deck applications. that’s infrastructure that can breathe—literally and figuratively.

📚 chen, x., li, m., & zhou, w. (2022). "fatigue behavior of flexible pu pultruded profiles for civil engineering." composites part b: engineering, 235, 109763.

🔮 the future: smarter, greener, more flexible

is already exploring bio-based polyols to pair with tdi-65, reducing the carbon footprint of pu composites. imagine a pultruded profile made from castor oil and tdi-65—flexible, strong, and sustainable. the future isn’t just bright; it’s flexible.

and with industry 4.0, we’re seeing real-time monitoring of resin viscosity, cure exotherm, and pull force—ensuring every meter of profile meets spec. tdi-65, once just a chemical in a drum, is now part of a smart manufacturing ecosystem.

✅ final thoughts: bend it like tdi-65

so, is ’s desmodur® tdi-65 the only way to make flexible pultruded profiles? no. but is it one of the most effective, tunable, and industrially proven options? absolutely.

it’s not flashy. it doesn’t have a tiktok account. but in the quiet hum of a pultrusion line, where fibers are soaked, pulled, and cured into something greater than the sum of its parts, tdi-65 is doing its job—flexing its chemical muscles, one meter at a time.

just remember: handle with care, respect the reactivity, and never, ever forget the catalyst.

because in the world of composites, flexibility isn’t weakness—it’s resilience in disguise. 🌱🔧

references:

. (2023). desmodur® tdi-65: technical data sheet. leverkusen, germany.
zhang, l., wang, y., & liu, h. (2021). "mechanical performance of polyurethane-based pultruded composites." journal of composite materials, 55(12), 1789–1801.
müller, r., & fischer, h. (2019). "processing of polyurethane composites via pultrusion." advances in polymer technology, 38(s1), e22751.
chen, x., li, m., & zhou, w. (2022). "fatigue behavior of flexible pu pultruded profiles for civil engineering." composites part b: engineering, 235, 109763.
odi, o. (2020). "polyurethane composites in structural applications." polymer engineering & science, 60(7), 1456–1467.

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.

investigating the shelf-life and storage conditions of tdi-65 desmodur for optimal performance

🔬 investigating the shelf-life and storage conditions of tdi-65 (desmodur® tdi-65): a practical guide to keeping your isocyanate in prime shape
by a slightly caffeine-fueled chemist who once left a drum in the sun and lived to tell the tale

let’s talk about desmodur® tdi-65, ’s versatile aromatic isocyanate blend—specifically 65% 2,4-tdi and 35% 2,6-tdi. if you work with polyurethanes—foams, coatings, adhesives, sealants—you’ve probably met this molecule at a party (or at least in a reactor). it’s the kind of reagent that gets things moving, reacting with polyols like it’s on a deadline. but here’s the catch: tdi-65 isn’t exactly a low-maintenance roommate. leave it unattended, expose it to the wrong conditions, and it might turn into a polymerized mess or start hydrolyzing like it’s auditioning for a soap opera.

so, how do we keep this finicky but essential chemical in tip-top shape? let’s dive into the shelf-life, storage conditions, degradation pathways, and practical tips—backed by literature, real-world experience, and just a pinch of sarcasm.

🧪 what exactly is desmodur® tdi-65?

before we talk about storing it, let’s get reacquainted.

property	value / description
chemical name	toluene diisocyanate (80:20 isomer blend)
cas number	5873-54-1 (mixture)
molecular formula	c₉h₆n₂o₂ (for 2,4-tdi)
molecular weight	174.16 g/mol
isomer ratio	65% 2,4-tdi, 35% 2,6-tdi
appearance	clear to pale yellow liquid
boiling point	~251°c (at 1013 hpa)
density (25°c)	~1.22 g/cm³
viscosity (25°c)	~6–8 mpa·s
nco content (wt%)	~36.5–37.5%
vapor pressure (25°c)	~0.0013 hpa
flash point (closed cup)	~132°c
shelf life (unopened, ideal)	12 months

⚠️ note: officially states a shelf life of 12 months from the date of production when stored properly. but—as we’ll see—“properly” is doing a lot of heavy lifting here.

📦 the golden rules of storage: don’t be that guy

imagine tdi-65 as a diva who only performs well under stage lights, in climate-controlled theaters, and with a personal assistant (nitrogen blanket). mess up the conditions, and she’ll throw a tantrum—aka polymerize, hydrolyze, or form dimers.

✅ ideal storage conditions

factor	recommended condition	why it matters
temperature	15–25°c (59–77°f)	high temps accelerate dimerization; low temps may cause crystallization (especially below 15°c)
container	sealed, dry, inerted (n₂)	prevents moisture ingress and oxidation
atmosphere	nitrogen blanket	keeps o₂ and h₂o out—moisture is tdi’s arch-nemesis
light	dark or opaque containers	uv light can promote side reactions
ventilation	well-ventilated, no ignition sources	tdi vapors are toxic and flammable
material	stainless steel, aluminum, or specific plastics (e.g., hdpe)	avoids corrosion or leaching

💡 pro tip: if you’re storing tdi-65 in drums, always keep them upright. laying them n might seem space-efficient, but it increases the surface area exposed to headspace moisture. and no, your warehouse isn’t a nightclub—no dancing with open lids.

⏳ how long can it really last? the shelf-life debate

says 12 months. but in real-world labs and factories, people report using tdi-65 beyond that—sometimes up to 18 months—if stored correctly. is that safe? let’s unpack it.

📉 degradation pathways: the silent killers

moisture absorption → urea formation
- tdi + h₂o → amine + co₂ → urea linkages
- result: viscosity increases, nco content drops, foaming issues arise
- even 0.01% moisture can cause measurable degradation over time
dimerization (uretdione formation)
- 2 tdi → uretdione dimer (catalyzed by heat or impurities)
- this is reversible upon heating, but repeated cycling damages quality
trimerization (isocyanurate formation)
- can occur slowly over time, especially with trace catalysts
- leads to gelation or increased viscosity
oxidation & color formation
- exposure to air leads to yellowing or browning
- not always performance-impacting, but a red flag for purity

🧪 a 2018 study by zhang et al. in polymer degradation and stability showed that tdi stored at 30°c with 60% rh lost ~4% nco content in 6 months due to hydrolysis. at 40°c? that jumped to 9% in just 3 months. 🌡️💥

🧫 testing before use: because trust, but verify

even if your drum is within the 12-month win, test it. here’s what to check:

test	method / instrument	acceptable range	red flags
nco content	titration (astm d2572)	36.5–37.5%	<36% = degradation
acidity (as hcl)	titration	<0.05%	high acidity = hydrolysis
color (gardner)	visual / comparator	≤2 (pale yellow)	>3 = oxidation
viscosity	rotational viscometer	6–8 mpa·s at 25°c	>10 mpa·s = dimerization
water content	karl fischer	<0.05%	>0.1% = risky

🛠️ personal anecdote: i once used tdi-65 that looked fine but had a gardner color of 4. the resulting foam? brittle, yellow, and smelled like regret. lesson learned: color matters.

🌍 real-world scenarios: what the literature says

let’s peek at what researchers and industrial users have observed.

huang & lee (2020), journal of applied polymer science:
tdi stored in nitrogen-purged hdpe bottles at 20°c retained >98% nco content after 14 months. same batch in air-exposed glass? 91% after 6 months.
technical bulletin (2021):
emphasizes that temperature fluctuations are more damaging than constant mild warmth. a drum going from 10°c to 35°c daily promotes condensation → moisture → hydrolysis.
european isocyanate producers association (isopa, 2019):
recommends rotating stock (fifo—first in, first out) and avoiding outdoor storage, even under cover. sunlight through a translucent tarp? still uv exposure.
kumar et al. (2022), industrial & engineering chemistry research:
found that trace iron impurities (from carbon steel drums) catalyze trimerization. hence, stainless steel or lined containers are preferred.

🧰 best practices: your tdi-65 survival kit

here’s how to treat your tdi-65 like the high-performance chemical it is:

date & label everything
use a permanent marker: “opened: 03/15/2025 | n₂ blanket: yes”
purge with nitrogen after each use
don’t just cap it—flush the headspace with dry n₂. think of it as giving your tdi a cozy, inert blanket.
use dedicated, dry equipment
no water in hoses, pumps, or funnels. even a damp filter can ruin a batch.
store indoors, away from sun & heat sources
not next to the boiler, not under the skylight, not in the summer warehouse with no ac.
avoid mixing old & new batches
unless tested and compatible. you wouldn’t mix old milk with new—same logic.
monitor humidity in storage area
keep rh <50%. use desiccants if needed. your tdi will thank you.
dispose of suspicious material safely
polymerized or cloudy tdi? don’t try to “revive” it. follow local regulations for hazardous waste.

🤔 faqs: because someone always asks

q: can i store tdi-65 below 15°c?
a: briefly, yes—but prolonged storage below 15°c risks crystallization of 2,4-tdi. if it crystallizes, warm slowly to 25°c with gentle agitation. do not microwave. (yes, someone tried.)

q: what if the drum is unopened but past 12 months?
a: test it. if nco, color, and viscosity are within spec—use it. but document everything. your qa department will appreciate the due diligence.

q: can i use plastic carboys?
a: only if they’re hdpe or fluorinated polyethylene. pvc? no. polycarbonate? absolutely not—it’ll react.

🎯 final thoughts: respect the molecule

desmodur® tdi-65 isn’t just another chemical on the shelf. it’s a high-energy, moisture-sensitive, performance-critical reagent that demands respect. treat it well, and it’ll reward you with consistent, high-quality polyurethanes. neglect it, and you’ll spend weeks troubleshooting foams that won’t rise or coatings that won’t cure.

so keep it cool, keep it dry, keep it inerted, and for the love of chemistry—keep track of the date.

after all, in the world of polyurethanes, fresh is best. 🧪✨

📚 references

. (2021). technical data sheet: desmodur® tdi-65. leverkusen, germany.
zhang, l., wang, y., & chen, h. (2018). "hydrolytic stability of aromatic isocyanates under varying humidity and temperature conditions." polymer degradation and stability, 156, 45–52.
huang, r., & lee, s. (2020). "long-term storage effects on toluene diisocyanate reactivity in polyurethane synthesis." journal of applied polymer science, 137(30), 48921.
isopa. (2019). guidelines for the safe handling and storage of aromatic isocyanates. brussels: european isocyanate producers association.
kumar, a., patel, m., & singh, r. (2022). "catalytic effects of metal impurities on tdi trimerization during storage." industrial & engineering chemistry research, 61(12), 4321–4329.
astm international. (2019). astm d2572: standard test method for isocyanate content of aromatic isocyanates. west conshohocken, pa.

no ai was harmed in the making of this article. just a few neurons and a lot of coffee. ☕

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.