热致形状记忆环氧乙烷-对苯二甲酸乙二酯多嵌段共聚物

Thermally Stimulated Recovery of Ethylene Oxide-Ethylene Terephthalate Segmented Copolymmers

不同软链段长度和不同硬链段含量的环氧乙烷－对苯二甲酸乙二酯被合成．分别测试了它们的拉伸样条的热致形变恢复．Ｓ形热致形变恢复曲线用最大形变恢复率（Ｒｆ），形变恢复温度（Ｔｒ）和形变恢复速度（Ｖｒ）表征．这些量的数值结果表明软链段的结晶状况决定热致形变恢复温度，最大形变恢复和形变恢复速度既依赖于硬链段所形成的物理交联点的稳定性，也受软链段长度变化的影响．

A series of ethylene oxide-ethylene terephthalate segmented copolymers with different soft segment length and different hard segment content have been synthesized. The thermally stimulated recovery of their stretched rectangular specimens are measured. The S-shaped thermally stimulated recovery curves are characterized by the maximum recovery( R f ) the recovery temperature( T r ) and the recovery velocity( V r ). The changes of these characteristic parameters show that the features of thermally stimulated shape memory effects of EOET segmented copolymers are as follows: The crystallinity of soft segments determines the recovery temperature. The maximum recovery and the recovery velocity depend on the stability of the physical crosslinks formed by the hard segments.At the same time they are influenced by the length of the soft segments,which is due to the entropic nature of the soft segment deformation recovery.