Preparation of rigid polyurethane foams using mixed metal complexes and tetraethylenepentamine as catalysts

Abstract

In this research, the catalysts for rigid polyurethane foams were developed by using metal-amine complexes [M1(tetraen)] (where; M1 = Cu, Zn, Ni, Co and Mn) and mixed metal-amine complexes [M2(tetraen):M3(tetraen)] (where; M2 = Cu, M3 = Zn, Ni, Co and Mn). The metal-amine and mixed metal-amine complexes were characterized by infrared spectroscopy, UV-visible spectroscopy, mass spectrometry and elemental analysis. Reaction times, physical and chemical properties of the prepared foams were investigated and compared with those prepared using commercial catalyst, dimethylcyclohexylamine (DMCHA). ATR-FTIR spectroscopy was used to characterize rigid polyurethane foams and determine isocyanate conversion. Rigid polyurethane foams catalyzed by mixed metal-amine complex of Cu(tetraen):Zn(tetraen) had good reaction times, volume and density. Density and compressive strength of the foams at NCO index of 150 catalyzed by Cu(tetraen):Zn(tetraen) were 49.8 kg/m3 and 341.9 kPa, respectively. They showed higher density and compressive strength than the foams catalyzed by DMCHA which were 45.8 kg/m3 and 309.7 kPa, respectively.