用二元胺扩链的聚丁二烯型聚氨酯弹性体的结构与性能

THE STRUCTURE AND PROPERTIES OF DIAMINE EXTENDED POLYBUTADIENE-BASED POLYURETHANE ELASTOMERS

以端羟基聚丁二烯、4,4’-二苯甲烷二异氰酸酯和4,4’-亚甲基双(2-氯苯胺)为原料,制备了具有优良物理机械性能的聚丁二烯型聚氨酯弹性体,研究了其结构与性能的关系。结果表明,该弹性体是一种微相分离接近完全的体系,硬段含量增加时微相分离则更趋完全。硬相微区中的大量氢键,具有强烈的物理交联作用。物理交联密度比化学交联密度大得多,对弹性体的结构和性能起着主要作用。

A series of polybutadiene-based polyurethane elastomers were synthesized from hydroxyl terminated polyhutadiene ( HTPB ) , 4,4/-diphenyl methane diisocyanate ( MDI ) and 3,3'-dichloro-4,4-diamino-diphenylme-thane ( MOCA ) .The relationship between the structure and properties of these polyurethane elastomers was studied. The results show that these polyurethane elastomers possess excellent mechanical properties. They have a two-phase structure.and the microphase segregation is nearly complete. The higher the hard segment content in the elastomer, the more complete the phase segregation. Within the hard segment domains, there are a large number of hydrogen bonds which are three-dimensional and lead to the unusually strong cohesion of the hard domains, which in turn results in more complete phase segregation. The secondary cross-linking density is far greater in number than that of the primary chemical crosslinking density and will exert more important effect on the structure and properties of these polyurethane elastomers.