化学交联反应注射成型聚氨酯脲的结构与性能关系

The Morphology and Property of Poly(urethane urea) Copolymers Formed by Reaction Injection Molding: Study on a Chemical Crosslinked System

用Ｌ－ＭＤＩ／ＤＥＴＤＡ／ＧＨ－３５０Ｅ制备了化学交联的ＲＩＭＰＵＵ弹性体，硬段含量为３７％。考察了催化剂浓度和种类对微相分离形态和力学性能影响。实验结果表明，提高催化剂浓度限制了化学交联体系ＲＩＭＰＵＵ的微相分离，使相间距有所增加，软段玻璃化温度几乎不受影响。实验制备的ＲＩＭＰＵＵ弹性体模量－温度稳定性好，拉伸强度为１２ＭＰａ，伸长率达２００％。

The effect of the different kind of catalysts and their concentration on the morphology and property of poly(urethane urea) (PUU) copolymers formed by reaction injection molding (RIM) was investigated. The poly(urethane urea) copolymers were based on a polyether triol, liquified 4,4′ diphenylmethane diisocyanates, and 3,5 diethyltoluene diamine and the hard segment content was 37%. The results showed that the degree of microphase separation of the chemical crosslinked copolymers was restricted by the high concentration of the catalysts. The interdomain spacing was located in the range of 83￣ 95 nm and the glass transform temperature was almost not affected. The RIM PUU copolymers showed superior modulus temperature dependence at elevated temperatures because of a comprehensive contribution of chemical crosslinked structure in soft segment, rigidity of hard segment and strong interaction of urea hydrogen bonds. The tensile strength of 12 MPa and elongation of 200% were achieved for the RIM PUU elastomer.