Polyurethane Catalyst for Rigid Foam

 Polyurethane catalysts for rigid foam, especially the kind used in PIR / PUR insulation systems 

Role of Catalysts in Rigid PU Foam

In rigid foam formulations, catalysts control:

• Blowing reaction (isocyanate + water → CO₂)

• Gelling reaction (isocyanate + polyol → polymer)

• Trimerization (for PIR foams)

The right balance = good flow, fine cell structure, fast cure, and high insulation performance.

Main Types of Catalysts for Rigid Foam

1️⃣ Amine Catalysts (Most Common)

Used to balance blowing vs. gelling.

Blowing Catalysts

Promote CO₂ generation and foam rise:

• DMCHA (Dimethylcyclohexylamine)

• TEDA / A-33 (Triethylenediamine, often in dipropylene glycol)

• BDMAEE

• PMDETA

 Improve foam rise, cell opening, and flow.

Gelling Catalysts

Promote polymer backbone formation:

• DABCO 8154

• DMDEE

• TMEDA

Increase foam strength and early demold.

2️⃣ Trimerization Catalysts (PIR / High-Index Foams)

Promote isocyanurate ring formation, critical for PIR boards and panels.

Typical examples:

• TMR-2 (CAS 62314-25-4) ✅

• Potassium acetate (KAc)

• Potassium octoate

• Quaternary ammonium salts

 Improve:

• Fire resistance

• Thermal stability

• Compressive strength

3️⃣ Metal Catalysts

Mainly for gelling control.

• Stannous Octoate (T-9, CAS 301-10-0)

• Bismuth carboxylates (low-toxicity alternative)

Often used in combination with amine catalysts.

 Typical Catalyst Packages by Application

 Rigid PUR Foam (Spray / Panel)

• A-33 (TEDA) → blowing

• DMCHA or BDMAEE → balance

• Small amount of T-9 → strength

 PIR Insulation Board / Sandwich Panel

• TMR-2 or potassium catalyst → trimerization

• TEDA → blowing control

• DMDEE → gel balance

 Rigid Foam for Pipes & Appliances

• Low-odor amines

• Controlled gelling catalysts

• Optional metal catalyst for cure speed

 Selection Tips

When choosing a catalyst system, consider:

• Foaming method (spray, continuous panel, discontinuous mold)

• Blowing agent (water, cyclopentane, pentane)

• Target cream / gel / tack-free time

• PIR index and fire rating requirements