化学交联对PPDI基聚碳酸酯型聚氨酯结构和性能的影响

Effects of Chemical Crosslink on Structures and Properties of PPDI-based Polycarbonate Urethane

用熔融预聚物法合成了以对苯二异氰酸酯(PPDI)、1,4-丁二醇(BDO)以及三羟甲基丙烷(TMP)为硬段,聚碳酸酯二醇(PCD)为软段的PPDI基聚碳酸酯型聚氨酯弹性体(PCU),研究了交联剂TMP用量对其结构与性能的影响。结果表明,随着TMP含量的增加,拉伸强度和断裂伸长率显著提高,并伴随压缩永久变形的明显下降;随着交联密度的增加,羰基的有序氢键化程度由23%下降至5%,软段相的玻璃化转变温度由-33℃升高到-17℃,表明PCU中软硬段相之间的微相分离程度减小;当TMP含量低于40%时,PPDI基PCU具有良好的耐热性和动态性能。

A series of chemical crosslinked polycarbonate urethanes(PCUs)were synthesized from 1,4-phenylene diisocyanate(PPDI),trimethylolpropane(TMP),1,4-butanediol(BDO)as hard segments and polycarbonate diol(PCD)as soft segments through melting prepolymer method.The effect of the content of TMP on structures and properties of PCUs were examined.The mechanical test indicated that the tensile strength and elongation at break increased with increasing content of TMP,while the compression set decreased.With increasing crosslink density of the PCUs,the degree of H-bonded carbonyl in the PCUs decreased from 23%to 5%,and the Tgvalue of the soft segment domains in the PCUs increased significantly from-33℃to-17℃,which indicated that the micro-phase separation of the PCUs was decreased.DMTA results showed that while the content of TMP was less than 40 %,PPDI-based polycarbonate urethane had excellent heat resistance and dynamic performance.