Polyisocyanurate foams preparation catalyzed by mixtures of copper-amine complexes/potassium 2-ethylhexanoate

Abstract

In this research, a new catalyst system for the preparation of polyisocyanurate (PIR) foam was developed. The mixture of copper-amine complex:potassium 2-ethylhexanoate (K-15) and metal-ethanolamine complex:K-15 were used as catalysts. Two copper-amine complexes and two metal-ethanolamine complexes, namely Cu(OAc)2(en)2, Cu(OAc)2(trien), Cu(OAc)2(EA)2 and Zn(OAc)2(EA)2, respectively; where en = ethylene diamine, trien = triethylenetetramine and EA = ethanolamine, were used as catalyst for blowing and gelling reactions. K-15 was used as a catalyst for trimerization reaction. These catalysts could be further used in the preparation of PIR forms without purification. Characterization of catalysts were done by using UV-visible spectroscopy. The factors investigated in the preparation of PIR foams were reaction times, foam density, NCO conversion, rise profile, temperature profile, compressive strength and morphology. PIR foams catalyzed by copper-amine complex:K-15 and metal-ethanolamine complex:K-15 were compared with those prepared from a commercial catalyst system, N,N´-dimethylcyclohexylamine (DMCHA):K-15. The experimental results showed that Cu(OAc)2(en)2:K-15, Cu(OAc)2(trien):K-15, Cu(OAc)2(EA)2:K-15 and Zn(OAc)2(EA)2:K-15 had better gelling catalytic activity than DMCHA:K-15. The ratio of catalyst:K-15 = 0.5:3 and the amount of water = 5 pbw are suitable for preparation of PIR foam.