Polyisocyanurate-Oxzolidone Modified Rigid Polyurethane Forms

The rigid polyurethane foam is widely used in many places. However,the application of rigid polyurethane foam is restricted in high temperaturebecause of the weakness of heat-resisting properties. In order to improvemechanical and heat-resisting properties of the polyurethane foam,Polyisocyanurate-oxzolidone modified rigid polyurethane foams weresynthesized by one-shot method. The isocyanurate rings and oxzolidone ringswere introduced into the backbones of the polyurethane. Besides, benzenerings were also introduced into the structure. The increase of crosslink densityand hard segment content lead to a higher Tg as well as better thermostability.Polymerization kinetics were monitored and analyzed by Fourier transforminfrared spectroscopy.1. The effects of catalyst, reactant on the molecular structure wereevaluated. The results proved that2-Ethyl-4-methylimidazole lead to moreoxzolidones ring while2,4,6-Tris(dimethylaminomethl)phenol preferred tocatalysis the formation of isocyanurate ring; the triethylenediaminehexahydrate is also a effective catalyst for introducing oxzolidone into themolecular backbone.2. Fourier transform infrared spectroscopy was used for monitoring thechange of characteristic groups, from which we concluded the polymerizationkinetics. It was found that urethane and isocyanurate groups were formed at first, and then they transferred to oxzolidone groups by reacting with epoxyresin.3. Several epoxy resin modified rigid polyurethane foams wereprepared by mould foaming way. Results indicated that as the dosage of epoxyresin increased, higher Tg and better thermostability were observed. The mostexcellent mechanical properties obtained when the epoxy resin was30wt%ofthe white materials.