溶液法合成聚氨酯的形状记忆材料及其性能

Performance of shape memory materials made of solution polymerized polyurethane

为了得到玻璃化转变温度高于 75℃、可在工程上应用的聚氨酯形状记忆材料 ,以 MDI、双酚 A环氧丙烷加成物和 1,4丁二醇为原料 ,甲苯为溶剂由两步溶液聚合法制备了一种新型的聚氨酯形状记忆材料 ,用 Fourier红外光谱对聚合物的结构进行了分析。以本工艺合成的聚氨酯形状记忆材料的玻璃化转变温度由 TMA方法测得 ,其温度范围在75～ 90℃之间。该聚合物试样在 10 0℃的记忆形状恢复时间不超过 10 s。研究表明 ,当 MDI的比例增加时 ,所得聚氨酯形状记忆材料的玻璃化转变温度升高 ,形状记忆恢复所需的时间缩短。用这种材料试制了铆钉 。

A kind of shape memory polymer with θ g higher than 75 ℃ was prepared using two-step solution polymerization with MDI, biphenol-A+propylen epoxide, 1, 4-butanediol as the material and toluene as the solvent. Its chain structure was determined by FT-IR spectrum. The glass transition temperature was between 75～90 ℃ and the restoration time was less than 10 s in boiling water. Increasing the proportion of MDI moiety in this shape memory polymer increased θ g and shortened the restoration time. A rivet with shape memory effect made of the shape memory polymer works quite well.