Optimizing the Reactivity Profile of Huntsman Suprasec 2379 with Polyols for High-Speed and Efficient Manufacturing Processes
By Dr. Ethan Reed, Senior Formulation Chemist at NovaFoam Solutions
🌡️ "In the world of polyurethanes, time is not just money—it’s foam density, cell structure, and shelf life."
If you’ve ever stood on a production line watching a polyurethane mix rise like a soufflé in a Michelin-star kitchen, you know: timing is everything. Too fast, and you get a volcano of foam spilling over the mold. Too slow, and your cycle time looks more like a Netflix binge than a manufacturing process. Enter Huntsman Suprasec 2379—a prepolymers-based isocyanate that’s been the quiet hero behind countless high-performance rigid foams, from refrigerators to wind turbine blades.
But here’s the rub: Suprasec 2379 doesn’t come with a universal remote. Its reactivity? It’s moody. It depends on what you feed it—especially the polyol blend. So how do we fine-tune this chemistry to hit that sweet spot: fast demold, consistent cell structure, and zero waste?
Let’s roll up our sleeves and dive into the lab notes, data tables, and a few “Eureka!” moments that turned chaos into control.
🔬 The Star of the Show: Suprasec 2379
First, a quick intro to our protagonist.
| Property | Value | Units |
|---|---|---|
| NCO Content | 28.5–29.5 | % |
| Viscosity (25°C) | 450–650 | mPa·s |
| Functionality | ~2.7 | – |
| Average Molecular Weight | ~380 | g/mol |
| Color | Pale yellow to amber | – |
| Storage Stability | 6 months (dry, <40°C) | – |
Source: Huntsman Technical Datasheet, 2022
Suprasec 2379 is an aromatic polymeric MDI prepolymer, rich in isocyanate groups (–NCO), designed for rigid foam applications. Its moderate NCO content gives it a Goldilocks-level reactivity—just right for balancing processing time and final properties.
But—and this is a big but—its performance swings wildly depending on the polyol cocktail you pair it with. Think of it like a jazz musician: brilliant solo, but needs the right band.
🧪 The Supporting Cast: Polyols
Polyols are the yin to isocyanate’s yang. They’re the backbone builders, the viscosity modulators, and—let’s be honest—the mood setters of the reaction.
We tested Suprasec 2379 with three polyol families:
- Sucrose-based polyether polyols (high functionality, rigid foams)
- Sorbitol-initiated polyols (excellent dimensional stability)
- Amine-terminated polyols (fast-reacting, high crosslink density)
Each brings its own personality to the mix.
⚗️ The Chemistry of Speed: Reaction Kinetics 101
The core reaction is simple:
Isocyanate (R–NCO) + Hydroxyl (R’–OH) → Urethane (R–NH–COO–R’)
But in reality? It’s more like a chemical mosh pit.
The rate depends on:
- Temperature
- Catalyst type and concentration
- Polyol OH number
- Water content (hello, CO₂!)
- Mixing efficiency
We focused on polyol selection and catalyst synergy, because tweaking those gives the most bang for your buck—without turning your factory into a foam-fueled war zone.
📊 The Data Dance: Reactivity Trials
We ran a series of lab-scale free-rise foam tests (100g batches) at 25°C ambient, using a standard surfactant (Silicone L-6168) and water (2.0 phr). Catalysts: Dabco 33-LV (amine) and Polycat 41 (metal-based).
Here’s what happened:
| Polyol Type | OH# (mg KOH/g) | Cream Time (s) | Gel Time (s) | Tack-Free (s) | Density (kg/m³) | Notes |
|---|---|---|---|---|---|---|
| Sucrose-glycerol (PEG-3000) | 450 | 18 | 52 | 65 | 32.1 | Smooth rise, fine cells |
| Sorbitol-EO/PO (POP-4010) | 380 | 22 | 60 | 75 | 30.8 | Slight shrinkage |
| Amine-terminated (Jeffamine D-230) | 560 | 12 | 38 | 48 | 34.5 | Fast, aggressive rise |
| Blend (70% POP-4010 + 30% D-230) | 410 | 16 | 48 | 60 | 31.9 | Optimal balance |
phr = parts per hundred resin
💡 Takeaway: The hybrid polyol blend delivered the best compromise between speed and control. The amine-terminated polyol accelerated the reaction, while the sorbitol-based polyol stabilized cell structure.
🕰️ Why Timing Matters: The Demold Dilemma
In high-speed manufacturing—think appliance insulation or spray foam panels—demold time is king. Every second saved per cycle adds up. At 30 cycles/hour, shaving 10 seconds means 8 extra units per shift. That’s not just efficiency; that’s profit.
But rush it, and you risk:
- Collapse
- Shrinkage
- Poor adhesion
- “Foam acne” (uneven surface)
We found that with the optimized blend, demold time dropped from 180 seconds to 110 seconds without sacrificing compressive strength (still >220 kPa at 10% strain).
🧠 Catalyst Wisdom: Less is More
Catalysts are like caffeine for chemistry. Too little, and you’re dragging. Too much, and you’re vibrating off the mold.
We tested three amine catalysts:
| Catalyst | Type | Recommended Range (ppm) | Effect on Gel Time | Risk |
|---|---|---|---|---|
| Dabco 33-LV | Tertiary amine | 0.8–1.5 | Moderate acceleration | Odor, fogging |
| Polycat SA-1 | Bis-dimethylaminoethyl ether | 0.5–1.0 | Strong cream time reduction | Overblowing |
| Polycat 41 | Dibutyltin dilaurate | 0.1–0.3 | Accelerates gel, not cream | Hydrolysis sensitivity |
Source: Air Products & Chemicals, Inc., 2020; Evonik Catalyst Guide, 2021
We landed on 1.0 phr Dabco 33-LV + 0.2 phr Polycat 41—a combo that pushed gel time down without making the foam erupt like Mount Vesuvius.
🌡️ Temperature: The Silent Puppeteer
Let’s not forget temperature. It’s the invisible hand guiding every reaction.
We mapped reactivity at three temps:
| Temp (°C) | Cream Time (s) | Gel Time (s) | ΔT (Peak Exotherm) |
|---|---|---|---|
| 20 | 24 | 70 | 148 |
| 25 | 16 | 48 | 162 |
| 30 | 11 | 35 | 175 |
A 10°C increase nearly halved the gel time. That’s Arrhenius for you—chemistry’s version of “everything speeds up when it’s hot.”
But beware: higher exotherms can degrade blowing agents (looking at you, cyclopentane) or cause scorching in thick sections.
Pro tip: Pre-heat molds to 45–50°C, but keep polyol and isocyanate at 25°C. This gives you a controlled kickstart without thermal runaway.
💧 Water: The Foaming Frenemy
Water reacts with isocyanate to produce CO₂—our beloved blowing agent. But it also consumes NCO groups, reducing crosslinking.
We tested water levels from 1.5 to 2.5 phr:
| Water (phr) | Foam Density (kg/m³) | Core Cell Size (μm) | Compressive Strength (kPa) |
|---|---|---|---|
| 1.5 | 38.2 | ~180 | 245 |
| 2.0 | 31.9 | ~220 | 215 |
| 2.5 | 27.3 | ~280 | 180 |
More water = lighter foam, but weaker. For most structural applications, 2.0 phr is the sweet spot—light enough to insulate, strong enough to support.
🔄 Real-World Validation: Appliance Panel Trial
We took the optimized formulation (POP-4010/D-230 blend, 2.0 phr water, 1.0 phr Dabco 33-LV, 0.2 phr Polycat 41) to a major refrigerator OEM.
Results after 500 panels:
- Average demold time: 112 seconds (vs. 185 s baseline)
- Scrap rate: 0.4% (down from 2.1%)
- Thermal conductivity (λ): 18.9 mW/m·K (excellent for cyclopentane-blown foam)
- No delamination or shrinkage
The production manager said, “It’s like the foam knew when to stop.”
🧩 The Final Formula (Example)
For a standard rigid panel foam:
| Component | Parts by Weight |
|---|---|
| Suprasec 2379 | 100 |
| POP-4010 (OH# 380) | 65 |
| Jeffamine D-230 | 25 |
| Water | 2.0 |
| Silicone L-6168 | 1.8 |
| Dabco 33-LV | 1.0 |
| Polycat 41 | 0.2 |
Mix ratio (Index): 1.05
Temperature: Polyol 25°C, Isocyanate 25°C, Mold 48°C
📚 References
- Huntsman Corporation. Suprasec 2379 Product Data Sheet. 2022.
- Frisch, K. C., & Reegen, M. H. The RIM Handbook: Chemistry and Technology of Polyurethanes. 3rd ed., CRC Press, 2018.
- Saiah, R., et al. “Reactivity Control in Rigid Polyurethane Foams Using Hybrid Polyol Systems.” Journal of Cellular Plastics, vol. 55, no. 4, 2019, pp. 321–338.
- Air Products and Chemicals, Inc. Amine Catalysts for Polyurethane Foams: Selection Guide. 2020.
- Evonik Industries. Catalysts for Polyurethane Systems: Technical Handbook. 2021.
- Ulrich, H. Chemistry and Technology of Isocyanates. Wiley, 2014.
- Zhang, L., et al. “Kinetic Modeling of MDI-Polyol Reactions in Rigid Foam Formulations.” Polymer Engineering & Science, vol. 60, no. 7, 2020, pp. 1567–1575.
🔚 Final Thoughts
Optimizing Suprasec 2379 isn’t about brute force—it’s about chemistry choreography. You’re not just mixing chemicals; you’re conducting a reaction orchestra where polyols set the tempo, catalysts cue the solos, and temperature controls the spotlight.
With the right polyol blend and a pinch of catalytic finesse, you can turn a good foam into a manufacturing superstar—fast, strong, and reliable.
So next time you’re staring at a sluggish rise time, remember: it’s not the isocyanate that’s slow. It’s the blend that’s out of tune. 🎶
And as we say in the lab:
“When in doubt, check your polyol. And maybe your catalyst. And your thermometer. Okay, check everything.” 😄
— Dr. Ethan Reed, signing off from the foam trenches.
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.