异氰脲酸酯改性聚氨酯弹性体的合成及研究

本文通过对异氰脲酸酯改性聚氨酯聚合反应过程的研究为基础，从各种异氰酸酯、聚醚二元醇、扩链剂及合适催化剂为反应组份，利用ＲＩＭ一步法和预聚物浇注二步法合成了系列异氰脲酸酯改性聚氨酯弹性体。通过对所制弹性体性能研究表明：在聚氨酯分子链中引入异氰脲酸酯环改性，可提高和改善弹性体的性能，随异氰脲酸酯含量的增加，弹性体的热稳定性和刚性显著增加。比较研究了两种不同方法合成的弹性体的结构形态和性能，结果表明一步法体系，由于其聚合速率快，体系中氨酯硬段和异氰脲酸酯硬段不同于二步法的较慢反应，它们没有足够时间发生相分离而互相混合，表现在ＤＳＣ曲线上只有一个Ｔｇｈ（硬段玻璃化温度），弹性体结构中含有氨酯、异氰脲酸酯相互混合的一个硬段区，结果表现在弹性体性能上，逊于结构中含有氨酯、异氰脲酸酯两个相分离的硬段区（有两个Ｔｇｈ）的二步法合成的弹性体材料。

PREPARATION AND STUDIES THE ELASTOMERS OF POLYURETHANE MODIFIED BY ISOCYANURATE

In this paper,the elastomers of polyurethame modified by isocyanurate were prepared by peaction injection molding (one-step) and prepolymer cast molding(two_step).The properties and Morphology of the prepared elestomers were studied and the results showed the polyurethane Crosslinked with isocyanurate exhibited a much higher heat resistance than "pure" polyurethone and their thermal stability incressed with increasing isocyanurate content in the system. Elastomers prepared by one-step method were inferior th those of their conterparts prepared by two-step method due to the random wide distributions of the hard segments(Which include both urethand and isocyanarate linkages)in the one-step system.