A line goes down because the catalyst drum is empty and the one supplier who sells that grade is on a six-week lead time. The label says a brand name, not a chemical name, so you cannot tell at a glance what else would drop in. That gap is the whole reason this page exists: nearly every workhorse polyurethane amine catalyst is a single, well-defined tertiary amine, and once you know which one is in the drum, you can second-source it by chemistry instead of by label.
The short version: Polyurethane amine catalysts are tertiary amines that speed up two competing reactions: the gelling reaction (isocyanate + polyol forms the urethane polymer and builds cure) and the blowing reaction (isocyanate + water forms CO₂ that makes the foam rise). Each catalyst leans one way. Triethylenediamine (TEDA) is the strong gelling standard, bis(2-dimethylaminoethyl) ether (BDMAEE) is the strong blowing standard, and grades like PMDETA and DMCHA sit in between for rigid foam. Because these are generic chemicals, RawSource grades are comparable to the named branded grades. For example, 33% TEDA in dipropylene glycol is comparable to Dabco 33-LV or Niax A-33, PMDETA is comparable to Polycat 5, DMCHA is comparable to Polycat 8, and BDMAEE is comparable to Niax A-1 or Dabco BL-11. Match the chemistry and the active concentration, then qualify it in your own formulation, because cream, gel, and tack-free times shift with everything else in the system.
How a polyurethane amine catalyst actually works
Polyurethane builds from two main reactions, and a tertiary amine catalyzes both. The gelling (or gel) reaction is isocyanate (–NCO) reacting with a polyol hydroxyl (–OH) to form the urethane linkage. That reaction builds molecular weight and viscosity; it is what turns a pourable liquid into a set, load-bearing polymer.
The blowing (or blow) reaction is isocyanate reacting with water. It first forms an unstable carbamic acid that decomposes to carbon dioxide and an amine; the CO₂ is the gas that expands the foam, and the amine goes on to form a urea linkage. In a foam, the gas has to be generated and trapped at the same rate the polymer gains enough strength to hold it.
A third reaction matters for rigid insulation: trimerization, where isocyanate groups react with each other to form thermally stable isocyanurate rings (the PIR in “polyiso”). Trimerization needs its own specialized catalysts and runs alongside the amine-driven gel and blow.
When the balance is off
The gel and blow reactions run at different rates depending on temperature, catalyst type, and catalyst loading, and the two have to stay in step. Get them out of step and the failure mode is predictable:
| Imbalance | What you see |
|---|---|
| Blow faster than gel | Gas outruns polymer strength: the foam over-expands then collapses, or you get internal splits and voids |
| Gel faster than blow | Cells close before full rise: shrinkage on cool-down, high density, tight skin, poor flow and fill |
| Both too fast | Short cream and rise window, scorch risk in thick sections, hard to pour or fill a mold |
| Both too slow | Long demold, soft green strength, poor cure, surface tack |
This is why catalyst selection is rarely one chemical. Most production systems pair a gelling catalyst with a blowing catalyst and tune the ratio until rise and cure line up for the part geometry and line speed.
The cross-reference table
Each grade below is a single, identifiable tertiary amine (or a standard solution of one). The “comparable to” column lists branded grades built on the same active chemistry at the same nominal concentration. That is a truthful comparison for second-sourcing, not a statement of affiliation. Confirm the active and the concentration on the branded grade’s own datasheet before you treat anything as a drop-in.
| RawSource grade | Chemistry (abbrev / CAS) | Blow vs gel lean | Comparable to | Typical use |
|---|---|---|---|---|
| Triethylenediamine | TEDA, solid · 280-57-9 | Strong gel (also drives blow) | Dabco Crystalline | The workhorse gel catalyst; flexible, molded, rigid, CASE |
| 33% TEDA in dipropylene glycol | 33% TEDA in DPG | Gel, balanced and pourable | Dabco 33-LV, Niax A-33 | Flexible slabstock and molded foam; the standard gel solution |
| Pentamethyldiethylenetriamine | PMDETA · 3030-47-5 | Blow-leaning; balances both in rigid | Polycat 5 | Rigid pour-in-place and appliance MDI systems; spray; good flow |
| N,N-dimethylcyclohexylamine | DMCHA · 98-94-2 | Gel-leaning, fairly balanced | Polycat 8, Niax C8 | Rigid insulation: spray, panel, board laminate, refrigeration |
| Bis(2-dimethylaminoethyl) ether | BDMAEE, neat · 3033-62-3 | Strong blow | (active in Niax A-1 / Dabco BL-11) | Flexible and high-resilience foam blow catalyst; RIM |
| 70% BDMAEE in dipropylene glycol | 70% BDMAEE in DPG | Strong blow, diluted and pourable | Niax A-1, Dabco BL-11 | Drop-in blow dosing for flexible and HR foam |
| 4-Methylmorpholine | NMM · 109-02-4 | Weak, blow-leaning, volatile | (general-purpose NMM grades) | CASE, co-catalyst, fast low-viscosity systems |
| 2-Methyl-TEDA | 2-MeTEDA | Delayed-action gel | (delayed-gel TEDA grades) | Molded flexible and CASE needing flow then a strong back-end cure |
Reading the table: the chemistry behind each lean
The lean of a tertiary amine is mostly structural. Blow catalysts tend to carry an ether oxygen two carbons from the nitrogen — exactly the structure of BDMAEE, which is why it is the reference blowing catalyst for flexible and high-resilience foam. The neat amine and the 70% solution in dipropylene glycol do the same job; the 70% DPG cut is what most lines buy because it meters cleanly, and it is the form sold under the Niax A-1 and Dabco BL-11 names.
Strong gel catalysts tend to have unhindered, alkyl-type nitrogens. Triethylenediamine (TEDA) is the cage-structure standard; it is the most effective single gelling catalyst in common use and still pushes the blow reaction as well. Pure TEDA is a hygroscopic solid, so foam plants almost always dose it as the 33% solution in dipropylene glycol, the chemistry behind Dabco 33-LV and Niax A-33.
The rigid-foam amines sit between the extremes. PMDETA is blow-leaning but balances both reactions, and at roughly 1.5 parts per hundred polyol it gives the flow and cure that pour-in-place MDI appliance systems need; that is the Polycat 5 chemistry. DMCHA is the cyclohexyl amine with a slight gel bias used across spray, panel, and refrigeration rigid foam — the Polycat 8 and Niax C8 chemistry. N-methylmorpholine is a weaker, more volatile amine often used in CASE and as a co-catalyst, and 2-methyl-TEDA is a delayed-action variant that holds back the gel so a molded part fills before it sets, then cures hard.
Choosing a catalyst by foam type
Selection follows the part, the isocyanate, and the line. Use this as a starting point, then tune the gel/blow ratio on your own equipment.
- Flexible slabstock (usually TDI). Pair a gel catalyst with a blow catalyst: the 33% TEDA/DPG gel grade plus a BDMAEE blow grade is the classic combination. Shift the ratio toward blow for more rise and openness, toward gel for firmer, higher-load foam.
- Molded and high-resilience flexible (TDI, MDI, or blends). Same gel-plus-blow base, with a delayed-action gel such as 2-methyl-TEDA added when you need the mix to flow and fill the tool before it builds strength.
- Rigid insulation (MDI): appliance, panel, board, spray, refrigeration. Lead with PMDETA for flow and blow and DMCHA for cure; add a dedicated trimerization catalyst when the target is PIR rather than straight PUR.
- CASE (coatings, adhesives, sealants, elastomers). These lean gel-dominant and are frequently low-foam: TEDA, DMCHA, or NMM, often alongside a metal co-catalyst for the urethane reaction.
Qualify the equivalent in your own system
A “comparable to” match means the active amine and its concentration are the same, which is what governs first-order reactivity. It does not promise identical processing, because the catalyst is one variable among many: polyol type, isocyanate index, water level, surfactant, blowing agent, and mix and mold temperatures all move the cream, gel, and tack-free times with it. Branded grades can also differ in trace co-catalysts, stabilizers, or low-emission chemistry that a single-active equivalent will not reproduce.
So treat any cross-reference as a sound starting point for a trial, not a guaranteed line-for-line swap. Run a side-by-side on your own equipment, watch the rise profile and demold, and check density, cell structure, and any odor or emission targets before you convert production. The same discipline applies to amine handling generally: these are corrosive, strong-smelling liquids and solids, and related amine-chemistry pitfalls like surface bloom show up elsewhere in formulation work, such as amine blush on cured epoxy.
DABCO® and POLYCAT® are registered trademarks of Evonik; NIAX® is a registered trademark of Momentive. RawSource is not affiliated with, authorized, or endorsed by these companies; product names are used only for nominative comparison.
Buying polyurethane amine catalysts
RawSource supplies the core tertiary-amine catalyst range for industrial polyurethane and CASE formulators — gelling grades (TEDA and 33% TEDA/DPG), blowing grades (BDMAEE neat and the 70% DPG solution), the rigid-foam amines (PMDETA and DMCHA), NMM, and the delayed-action 2-methyl-TEDA — in drums, IBCs, and bulk with CoA documentation. Tell us the branded grade you run today, your foam type, and your target rise and demold times, and request a sample to qualify the equivalent on your own line.
Frequently asked questions
What is DABCO?
DABCO is a brand name for triethylenediamine (TEDA), CAS 280-57-9, a tertiary-amine catalyst used to speed up polyurethane reactions. It is one of the most effective gelling catalysts, meaning it accelerates the isocyanate-plus-polyol reaction that builds the polymer. The same chemistry is sold generically as triethylenediamine, and most foam plants dose it as a 33% solution in dipropylene glycol.
What is the difference between a blowing catalyst and a gelling catalyst?
A gelling catalyst speeds up the isocyanate-plus-polyol reaction that forms the urethane polymer and builds cure; a blowing catalyst speeds up the isocyanate-plus-water reaction that releases CO₂ and makes the foam rise. Most amines do both, but lean one way. Triethylenediamine leans gel; bis(2-dimethylaminoethyl) ether leans blow. Foam systems balance the two so the gas is generated as fast as the polymer can hold it.
Is there a Polycat 5 or Polycat 8 equivalent?
Polycat 5 is pentamethyldiethylenetriamine (PMDETA, CAS 3030-47-5), so our PMDETA is the comparable generic grade, used as a blow-leaning catalyst for rigid MDI foam. Polycat 8 is N,N-dimethylcyclohexylamine (DMCHA, CAS 98-94-2), so our DMCHA is the comparable grade for rigid insulation. Match the active and concentration, then qualify it in your formulation.
Is there a Niax A-1 or Dabco BL-11 equivalent?
Both Niax A-1 and Dabco BL-11 are built on bis(2-dimethylaminoethyl) ether (BDMAEE) supplied as roughly a 70% solution in dipropylene glycol. Our 70% BDMAEE in dipropylene glycol is the comparable grade, and we also stock neat BDMAEE. It is a strong blowing catalyst for flexible and high-resilience foam.
What catalysts does rigid polyurethane foam use?
Rigid MDI foam typically uses a blow-leaning amine such as PMDETA for flow and a gel-leaning amine such as DMCHA for cure, often together. When the target is polyisocyanurate (PIR) rather than straight polyurethane, a dedicated trimerization catalyst is added to build the thermally stable isocyanurate ring.
Can I drop a comparable catalyst straight into my formulation?
Treat it as a strong starting point, not a guaranteed swap. Matching the active amine and its concentration sets first-order reactivity, but cream, gel, and tack-free times also depend on your polyol, index, water, surfactant, blowing agent, and temperatures. Branded grades may also carry trace co-catalysts or low-emission chemistry a single-active equivalent will not reproduce. Run a side-by-side and confirm rise, demold, density, and cell structure before converting production.
Editorial note. This article is general technical guidance for polyurethane and CASE formulation professionals; it is not a specification or formulation advice. Catalyst selection, gel/blow balance, and processing behavior depend on your specific polyol, isocyanate, index, water level, additives, and equipment, and must be validated on your own system; the Certificate of Analysis governs the grade you buy. Brand names are used only for truthful nominative comparison where our product is the same generic chemistry, and equivalence of processing must be confirmed by trial. Amine catalysts are corrosive and strongly odorous and can cause skin and eye burns and respiratory irritation — review the current Safety Data Sheet (SDS) and use appropriate PPE and ventilation before handling. Products are sold for industrial and professional use only. Nothing here is a medical, health, or safety claim. RawSource makes no warranty, express or implied, and assumes no liability for use of this information.
