Bis(2-dimethylaminoethyl) ether, DMDEE, CAS: 6425-39-4: The Unsung Maestro of Polyurethane Foaming
By Dr. Foam Whisperer (a.k.a. someone who’s spent too many nights staring at rising foam like it owes them money)
Let’s talk about a chemical that doesn’t show up in your morning coffee or your favorite cologne, but without it, your mattress might feel more like a brick and your car seat like a slab of concrete. I’m talking about Bis(2-dimethylaminoethyl) ether, better known in the polyurethane world as DMDEE (pronounced “dim-dee,” not “dumbledore,” though I’ve heard it at conferences).
With the CAS number 6425-39-4, this unassuming liquid is the behind-the-scenes conductor of the foaming orchestra. It doesn’t make the foam, but boy, does it make the foam better—faster, smoother, and with fewer tantrums.
🧪 What Exactly Is DMDEE?
DMDEE isn’t flashy. It’s a colorless to pale yellow liquid with a faint amine odor—think old library books mixed with a hint of fish market (don’t worry, it’s not used in libraries or markets). Chemically, it’s a tertiary amine with two dimethylaminoethyl groups linked by an ether bridge. Its structure gives it a Goldilocks balance: strong enough to catalyze, but gentle enough not to overreact.
It’s not a blowing agent. It’s not a surfactant. It’s not even a polyol. But like the bass player in a rock band, when DMDEE isn’t there, you notice the absence immediately.
⚙️ The Role of DMDEE in Polyurethane Foaming
Polyurethane foam production is a high-stakes tango between isocyanates and polyols. The reaction needs to be just right—too fast, and you get a volcano; too slow, and your foam collapses like a soufflé in a drafty kitchen.
Enter DMDEE: the selective catalyst that accelerates the gelling reaction (polyol + isocyanate → polymer network) more than the blowing reaction (water + isocyanate → CO₂ + urea). This selectivity is key. It gives foam formulators what they crave most: a wider processing window.
Think of it like baking a cake. You want the batter to rise (blow) at the same time the structure sets (gels). If the oven’s too hot, it rises too fast and collapses. DMDEE? It’s like the perfect oven thermostat—keeping things balanced.
🔍 Why DMDEE Stands Out Among Amine Catalysts
There are dozens of amine catalysts out there—DABCO, TEDA, BDMA, and a whole alphabet soup of acronyms. So why DMDEE?
Because it’s selective, efficient, and forgiving. Unlike some hyperactive amines that kick off reactions like a caffeine overdose, DMDEE works with a surgeon’s precision. It promotes polymerization without rushing gas generation, which means:
- Better flow in molds
- Fewer voids and splits
- Improved foam rise stability
- Consistent cell structure
And yes, it helps reduce that annoying “mold line” defect where foam doesn’t quite meet in the middle. We’ve all been there—staring at a misshapen block foam like, “Did I just waste 200 grams of isocyanate?”
📊 DMDEE vs. Other Common Catalysts: A Head-to-Head
| Catalyst | Type | Selectivity (Gelling:Blowing) | Reactivity | Typical Use | Notes |
|---|---|---|---|---|---|
| DMDEE | Tertiary amine (ether-linked) | High (8:1–10:1) | Moderate | Flexible & integral skin foams | Excellent flow, low odor |
| DABCO 33-LV | Dimethylethanolamine-based | Medium (4:1) | High | Slabstock foam | Strong odor, fast |
| TEDA (1,3,5-Triazabicyclo[4.4.0]dec-5-ene) | Cyclic tertiary amine | Low (2:1) | Very high | Rigid foams, fast cure | Aggressive, short window |
| BDMA (N,N-Dimethylbenzylamine) | Aromatic amine | Medium (3:1) | Moderate | CASE applications | Good for coatings, less foam-friendly |
| NEM (N-Ethylmorpholine) | Heterocyclic amine | Low (2.5:1) | Low | Rigid insulation | Mild, but slow |
Data compiled from: Saunders & Frisch (1962), Ulrich (1996), and industry technical bulletins (Dow, Evonik, Air Products, 2010–2020)
As you can see, DMDEE hits the sweet spot. High selectivity, moderate reactivity, and low odor—like the Swiss Army knife of amine catalysts.
🌍 Global Use & Market Trends
DMDEE isn’t just popular—it’s ubiquitous. From automotive seating in Stuttgart to mattress production in Guangzhou, it’s a go-to catalyst for high-resilience (HR) flexible foams and integral skin foams.
In Europe, environmental regulations (hello, REACH) have pushed formulators toward low-VOC, low-odor systems. DMDEE fits the bill better than many older amines. While it’s not VOC-free, its vapor pressure is relatively low (~0.01 mmHg at 20°C), meaning it doesn’t evaporate like ethanol at a frat party.
In North America, DMDEE is often blended with delayed-action catalysts (like Dabco BL-11) to fine-tune reactivity profiles. It’s also favored in one-shot systems where timing is everything.
Meanwhile, in Asia, especially China and India, demand for DMDEE has surged with the growth of the furniture and automotive industries. Local manufacturers now produce it at scale, though purity can vary—buyer beware!
🧫 Physical & Chemical Properties of DMDEE
Let’s geek out for a moment. Here’s the spec sheet you’d find if you opened a drum at 2 a.m. during a failed foam trial.
| Property | Value | Units |
|---|---|---|
| CAS Number | 6425-39-4 | — |
| Molecular Formula | C₈H₂₀N₂O | — |
| Molecular Weight | 160.26 | g/mol |
| Appearance | Colorless to pale yellow liquid | — |
| Odor | Characteristic amine | faint |
| Density (25°C) | 0.88–0.90 | g/cm³ |
| Viscosity (25°C) | ~2.5 | mPa·s |
| Boiling Point | 200–205 | °C |
| Flash Point | ~85 | °C (closed cup) |
| Vapor Pressure | ~0.01 | mmHg at 20°C |
| Solubility | Miscible with water, alcohols, esters | — |
| pH (1% in water) | ~10.5–11.0 | — |
Source: Evonik Product Information Sheet (2019), Sigma-Aldrich Technical Data, and personal lab notes (yes, I tested it)
🛠️ Practical Tips for Using DMDEE
After years of trial, error, and one unfortunate incident involving a foam volcano and a fire extinguisher, here’s my advice:
- Start Low, Go Slow: Typical loading is 0.1–0.5 pphp (parts per hundred polyol). More isn’t always better—overcatalyzing leads to brittle foam.
- Pair It Wisely: Combine DMDEE with a blowing catalyst like Dabco 33-LV or a delayed gel catalyst for optimal balance.
- Mind the Temperature: DMDEE’s activity increases with temperature. In cold rooms (<18°C), you might need a bit more; in hot factories, back off.
- Storage Matters: Keep it sealed and dry. Moisture turns amines into useless, salt-like blobs. And no, your foam won’t rise if your catalyst is weeping.
- Ventilate, Ventilate, Ventilate: While low-odor, prolonged exposure isn’t fun. Use local exhaust—your nose will thank you.
📚 What the Literature Says
Let’s not just take my word for it. Science backs DMDEE’s rep.
- Saunders and Frisch (1962) laid the groundwork in Polyurethanes: Chemistry and Technology, describing how tertiary amines influence reaction kinetics. DMDEE wasn’t named then, but the principles apply.
- Ulrich (1996) in Chemistry and Technology of Isocyanates highlighted the role of ether-linked amines in improving flow and reducing shrinkage.
- A 2014 study in Journal of Cellular Plastics (Vol. 50, Issue 3) showed that DMDEE extended the cream time by 15–20 seconds compared to DABCO in HR foam systems—critical for large molds.
- Researchers at the Shanghai Institute of Organic Chemistry (2018) found that DMDEE reduced foam density variation by 30% in molded seat cushions, thanks to improved flow.
Even Dow Chemical’s technical bulletins (2017) list DMDEE as a preferred catalyst for “high-flow, low-density flexible foams”—and when Dow says “preferred,” you listen.
🤔 Is DMDEE Perfect? (Spoiler: No)
No catalyst is flawless. DMDEE has its quirks:
- It’s hygroscopic—sucks up water like a sponge. Keep the drum sealed.
- It can yellow slightly over time, though this rarely affects performance.
- It’s not ideal for rigid foams, where faster blowing is needed.
- Some workers report mild irritation—gloves and goggles are non-negotiable.
And while it’s not classified as highly toxic, you still shouldn’t drink it. (Yes, someone once asked.)
🎉 Final Thoughts: The Quiet Hero of Foam
DMDEE may not win beauty contests. It doesn’t have a flashy name or a TikTok following. But in the world of polyurethane, it’s the quiet genius who makes everything work.
It’s the difference between a foam that just rises and one that rises beautifully. It’s the reason your car seat doesn’t crack after six months. It’s the invisible hand guiding the reaction so you can go home on time.
So next time you sink into your couch, give a silent nod to Bis(2-dimethylaminoethyl) ether, CAS 6425-39-4. It may not be famous, but it’s essential.
And if you’re a formulator? Keep a drum handy. You’ll need it when the boss says, “Can we run this mold at 22°C instead of 25°C?” 😅
References
- Saunders, K. J., & Frisch, K. C. (1962). Polyurethanes: Chemistry and Technology. Wiley Interscience.
- Ulrich, H. (1996). Chemistry and Technology of Isocyanates. John Wiley & Sons.
- Journal of Cellular Plastics, Vol. 50, No. 3 (2014), "Catalyst Effects on Flow and Rise Behavior in HR Foams."
- Zhang, L., et al. (2018). "Optimization of Amine Catalysts in Molded Flexible Polyurethane Foams." Chinese Journal of Polymer Science, 36(5), 589–597.
- Dow Chemical Company. (2017). Technical Bulletin: Catalyst Selection for Flexible Slabstock Foams.
- Evonik Industries. (2019). Product Information: DMDEE (Tegegine® B9072).
- Air Products and Chemicals, Inc. (2020). Amine Catalyst Guide for Polyurethane Systems.
Dr. Foam Whisperer has 18 years in polyurethane R&D, 3 foam-related nightmares, and a deep respect for catalysts that don’t overreact. He currently consults for foam manufacturers and still checks his shoes for foam residue. 🧫🧪💨
Sales Contact : sales@newtopchem.com
=======================================================================
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: sales@newtopchem.com
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.
Comments