Abstract:
In this research, polyurethane foams were prepared from microwave-assisted glycolyzed products of poly(ethylene terephathalate) or PET. Post-consumer PET bottles were depolymerized with diethylene glycol at PET:glycol molar ratio of 1:4, under microwave energy using zinc acetate, sodium carbonate and sodium bicarbonate as a catalyst at 0.5% by weight. It was found that all catalysts were able to be used effectively to complete the glycolysis. The glycolyzed products were reacted with diphenylmethane diisocyanate in order to synthesize polyurethane foam in the presence of poly(ethylene glycol) of molecular weight of 4,000 and 6,000 as a chain extender. It was found that the type of catalyst and chain extender affected properties and morphology of the prepared foam. The prepared foam contained mostly closed cells. It was found that polyurethane foam prepared from glycolyzed products using sodium carbonate and sodium bicarbonate as a catalyst had more uniform cells than using zinc acetate. However, foam prepared from glycolyzed products which used zinc acetate possed better compression set and higher density. The degradation temperatures were similar for all foams. When poly(ethylene glycol) of the molecular weight of 4,000 was used, it gave better foam uniformity, higher density, better compression set and higher glass transition temperature while the degradation temperature were slightly lower.