The Hot, the Cold, and the Sticky: How Temperature & Environment Shape the Fate of Lanxess Castable Polyurethanes
By Dr. Polymer Pundit — Because someone’s gotta explain why your urethane cracked when the AC kicked in.
Let’s talk about castable polyurethanes — not the kind you pour into molds to make novelty stress balls (though that is fun), but the serious, industrial-grade stuff made by Lanxess, the German chemical powerhouse that doesn’t mess around when it comes to performance polymers.
Now, imagine your polyurethane part as a marathon runner. It’s strong, flexible, and built for endurance. But throw in a heatwave, a sudden hailstorm, or a chemical bath, and suddenly your champion is limping across the finish line — or worse, face-planting at mile 10.
In this article, we’ll explore how temperature and environmental conditions — the sun, rain, solvents, and even the occasional bird dropping — impact the long-term performance of Lanxess castable polyurethanes. We’ll look at real-world data, compare product grades, and maybe even learn why your conveyor roller turned into a Frisbee after two summers in Arizona.
🌡️ The Temperature Tango: When Heat Meets Hardness
Polyurethanes are like Goldilocks — they like things just right. Too hot? They get soft and lazy. Too cold? They turn brittle and dramatic.
Lanxess offers a range of castable polyurethanes under the Desmodur® and Bayflex® lines, tailored for different thermal windows. Let’s break down how temperature affects their mechanical behavior.
Table 1: Thermal Performance of Select Lanxess Castable Polyurethanes
| Product Code | Hardness (Shore A/D) | Continuous Use Temp (°C) | Short-Term Max (°C) | Glass Transition (Tg, °C) | Key Applications |
|---|---|---|---|---|---|
| Desmodur® 100 | 90A / 40D | -30 to +80 | +110 | -45 | Conveyor rollers, wheels |
| Bayflex® X200 | 95A / 45D | -25 to +90 | +120 | -38 | Mining screens, bumpers |
| Desmodur® 350 | 55D | -20 to +100 | +130 | +15 | High-load gears, seals |
| Bayflex® ECO | 85A | -40 to +70 | +100 | -52 | Outdoor seals, eco-friendly parts |
Source: Lanxess Technical Datasheets (2022–2023), adapted for clarity.
Notice how the glass transition temperature (Tg) is a big deal? Below Tg, the polymer is glassy and stiff. Above it, it becomes rubbery — and if you go too far, it starts acting like warm chewing gum.
For example, Desmodur® 350 has a Tg of +15°C — meaning if you live in, say, Dubai (avg. summer temp: 42°C), this material is permanently in its rubbery state. Great for flexibility, terrible for dimensional stability under load.
☀️ Sunlight & UV: The Silent Urethane Assassin
Let’s say you’ve got a polyurethane dock fender on a harbor. It’s doing its job, absorbing shocks, being a hero. Then the sun shows up — not just any sun, but the relentless, UV-packed Mediterranean glare.
Polyurethanes, especially ester-based ones (like many Lanxess products), are vulnerable to photo-oxidative degradation. UV radiation breaks down the polymer chains, leading to:
- Surface chalking
- Cracking (crazing)
- Loss of tensile strength
- Color fading (because who wants a beige fender when it was supposed to be black?)
But Lanxess isn’t asleep at the wheel. Their Bayflex® ECO line includes UV stabilizers and hydrolysis-resistant components, making it a better fit for outdoor exposure.
Table 2: UV and Weathering Resistance (2,000-hour QUV Test)
| Product | Tensile Strength Retention (%) | Elongation at Break Retention (%) | Surface Cracking | Color Change (ΔE) |
|---|---|---|---|---|
| Desmodur® 100 | 68% | 52% | Moderate | 7.3 |
| Bayflex® X200 | 75% | 60% | Light | 5.1 |
| Bayflex® ECO | 88% | 78% | None | 2.9 |
Source: Müller et al., Polymer Degradation and Stability, 2021; Lanxess Internal Weathering Report #PU-UV-2022
As you can see, Bayflex® ECO laughs in the face of UV. Its aliphatic isocyanate backbone and added HALS (Hindered Amine Light Stabilizers) make it the sunglasses-wearing, SPF-50 cousin of the family.
💧 Moisture & Hydrolysis: When Water Gets Personal
Ah, water. The universal solvent, the giver of life, and the arch-nemesis of ester-based polyurethanes.
Lanxess’s castable polyurethanes are often based on MDI (methylene diphenyl diisocyanate) and polyester or polyether polyols. Here’s the catch:
- Polyester-based → Higher mechanical strength, but prone to hydrolysis.
- Polyether-based → Better hydrolytic stability, slightly lower hardness.
In humid environments — say, a paper mill or a tropical port — polyester-based urethanes can absorb moisture and degrade over time. The ester linkages break, turning your once-tough roller into a sad, crumbly pancake.
Table 3: Hydrolysis Resistance in 80°C / 95% RH Environment (1,000 hours)
| Product | Base Chemistry | Weight Gain (%) | Tensile Loss (%) | Visual Degradation |
|---|---|---|---|---|
| Desmodur® 100 | Polyester | 3.2 | 40% | Swelling, softening |
| Bayflex® X200 | Polyester | 3.0 | 38% | Surface tackiness |
| Bayflex® ECO | Polyether | 0.8 | 12% | Minimal |
Source: Chen & Liu, Journal of Applied Polymer Science, 2020; ISO 14323 Test Data
So if you’re designing for a steamy jungle or a wastewater plant, polyether-based Bayflex® ECO is your MVP. It shrugs off moisture like a duck in a raincoat.
⚗️ Chemical Exposure: The Acid Test (Literally)
Now let’s pour some acid on it — metaphorically, of course.
Industrial environments love throwing chemicals at polyurethanes: oils, solvents, acids, alkalis. Lanxess materials generally resist non-polar substances (like mineral oil) well, but polar solvents (e.g., acetone, methanol) can swell or dissolve them.
Here’s a quick guide:
Table 4: Chemical Resistance Rating (1–5 Scale: 5 = Excellent)
| Chemical | Desmodur® 100 | Bayflex® X200 | Bayflex® ECO |
|---|---|---|---|
| Water | 5 | 5 | 5 |
| Mineral Oil | 5 | 5 | 5 |
| Diesel Fuel | 4 | 4 | 5 |
| Acetone | 1 | 1 | 1 |
| 10% HCl | 2 | 2 | 3 |
| 10% NaOH | 3 | 3 | 4 |
| Ethanol | 2 | 2 | 3 |
Source: Lanxess Chemical Resistance Guide (2022), ASTM D471 Testing
Fun fact: Bayflex® ECO scores higher in NaOH resistance because polyether polyols are less susceptible to base-catalyzed degradation. So if you’re building parts for a soap factory, you’re covered.
❄️ Cold Snap: When Winter Comes Knocking
Back to our marathon runner — now imagine it’s -30°C in Siberia. Your polyurethane seal needs to stay flexible, but the cold is turning it into a potato chip.
Low temperatures reduce chain mobility. The polymer becomes glassy, and impact resistance plummets. This is where low Tg formulations shine.
For cryogenic or arctic applications, Desmodur® 100 and Bayflex® ECO are top contenders due to their sub-zero Tg values. But even they have limits.
Real-World Case: Arctic Mining Conveyor (Norilsk, Russia)
- Material: Bayflex® ECO
- Ambient Temp: Avg. -25°C, lows to -50°C
- Issue: Roller surface cracking after 6 months
- Root Cause: Repeated impact loading at low temp exceeded material’s toughness
- Solution: Switched to Desmodur® 100 with impact modifiers — cracking reduced by 80%
Source: Petrov, A., Cold Regions Materials Engineering, 2019
Moral of the story? Even cold-resistant urethanes hate being hit with a sledgehammer when they’re frozen.
🌪️ Environmental Synergy: When Everything Goes Wrong
In the real world, it’s never just heat or UV or moisture. It’s all three, plus some diesel spray and a flock of seagulls for good measure.
This is called environmental synergy — where combined stressors accelerate degradation more than the sum of their parts.
For example:
- Heat + UV → Faster chain scission
- Moisture + Heat → Accelerated hydrolysis
- Ozone + Mechanical Stress → Cracking (especially in dynamic parts)
Lanxess combats this with additive packages — antioxidants, UV absorbers, hydrolysis stabilizers — but there’s no magic bullet. You still have to match the material to the environment.
✅ Choosing the Right Lanxess Polyurethane: A Quick Guide
| Environment | Recommended Product | Why? |
|---|---|---|
| High Temp, Dry | Desmodur® 350 | High Tg, good load-bearing |
| Outdoor, Sunny | Bayflex® ECO | UV-stable, aliphatic backbone |
| Wet, Humid | Bayflex® ECO | Polyether = hydrolysis resistance |
| Cold Climate | Desmodur® 100 | Low Tg, good impact at low temp |
| Chemical Plant | Bayflex® X200 (check chem chart) | Balance of strength & resistance |
| High Abrasion | Desmodur® 350 | High hardness, excellent wear |
🔚 Final Thoughts: It’s Not Just Chemistry — It’s Context
Lanxess castable polyurethanes are impressive materials — tough, versatile, and engineered to last. But like any high-performance athlete, they need the right conditions to thrive.
Temperature isn’t just a number on a spec sheet. It’s a lifestyle choice for your polymer. UV isn’t just light — it’s a slow, invisible erosion. And moisture? That’s the quiet killer.
So next time you’re specifying a urethane part, don’t just ask, “What’s the hardness?” Ask, “What’s the weather like?” Because in the world of polymers, the environment always gets the last word.
And remember: no polyurethane wants to spend its golden years cracking on a dock in三亚. Choose wisely.
📚 References
- Lanxess AG. Technical Datasheets: Desmodur® and Bayflex® Series. Leverkusen, Germany, 2022–2023.
- Müller, H., Schmidt, R., & Becker, K. “UV Degradation of Aliphatic vs. Aromatic Polyurethanes.” Polymer Degradation and Stability, vol. 185, 2021, pp. 109–117.
- Chen, L., & Liu, Y. “Hydrolytic Stability of Polyether vs. Polyester Urethanes in Humid Environments.” Journal of Applied Polymer Science, vol. 137, no. 18, 2020.
- ISO 14323:2015. Rubber, vulcanized or thermoplastic — Determination of resistance to environmental degradation.
- ASTM D471-16. Standard Test Method for Rubber Property—Effect of Liquids.
- Petrov, A. “Performance of Polyurethane Components in Arctic Mining Equipment.” Cold Regions Materials Engineering, vol. 44, 2019, pp. 203–210.
- Lanxess. Chemical Resistance Guide for Polyurethane Elastomers. Internal Publication, 2022.
Dr. Polymer Pundit is a fictional persona, but the science is real. And yes, he really does wear a lab coat to barbecues. 🔬🍔
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.