嵌段聚酯型聚脲氨酯弹性体的合成与表征

本研究首先利用先本体预聚后溶液扩散链聚合的两步法合成了基于MDl,乙二胺和聚已二酸丁二醇酯(分子量1975和1228)的两系列嵌段聚酯型聚脲氨酯(PUU)弹性体,接着用元素分析,力学试验,GPC,IR,WAXD和SEM等技术对样品进行了全面表征.结果表明:PUU材料具有优异的力学性能.由WAXD和SEM研究发现:PUU中的软、硬段都是部分结晶的,晶体的尺寸依赖于硬段含量和软段分子量的变化.认为:PUU中存在着软、硬段两相微区,硬段微区被分散在由软段形成的基体中充当物理交联作用使材料表现出橡胶弹性性质.

SYNTHESIS AND CHARACTERIZATIONS OF SEGMENTED POLYESTER POLYURETHANEUREA ELASTOMERS

n the present study,two series of novel segmented polyester polyurethaneurea(PUU)elastomers based on 4.4'-diphenylmethane diisocyanate(MDl),ethylene diamine(ED)and polybutylene adipate(PBA)(M.W.1975 and M.W.1228)were synthesized by two step methods in which the bulk Prepolymerization was first done and then the solution extending polymerization.The samples were characterized by various techniques,such as Element Analysis.Mechanical Experiment.GPC.IR.WAXD and SEM.etc.The results show that the materials are of excellent mechanical properties.It is found from the studies of WAXD and SEM that the soft and hard segments of PUU are crystalline partially and the sizes of crystalline depand on the changes of the hard segment content and soft segment molecular weight.It is believed that two phase domains of the soft and hard segments exist in PUU and the hard segment domains acting as physical cross-linking are dispersed in the matrix formed by the soft segment chains to make the materials exhibit rubbery elastic oroperpies.