一种赋予聚乳酸水诱导形状记忆的聚合物

本发明涉及一种赋予聚乳酸(PLA)水诱导形状记忆的嵌段聚合物。该嵌段聚合物主链由羟基封端的乙烯基聚硅氧烷(PMVS)嵌段、聚四氢呋喃(PTMG)嵌段以及聚己内酯(PCL)嵌段组成，侧链为聚丙烯酸(PAA)。其中，PMVS嵌段除主链聚硅氧烷柔韧性好外，活性双键侧基引发丙烯酸(AA)聚合得到PAA侧链，并且PAA链段的极性羧基可以很大程度上提高PLA的亲水性。PTMG嵌段不仅可以提高PLA的韧性，而且其低玻璃化转变温度可以在低温下实现融化与重结晶过程。PCL嵌段可以改善嵌段共聚物与PLA的相容性。该嵌段聚合物(PCL-PTMG-PCL-(PMVS-s-PAA)-PCL-PTMG-PCL)制备过程简单，不但较低温度下(20-50℃)即可实现融化与重结晶，而且具有超强吸水性，能够赋予PLA水诱导形状记忆效应，且形状记忆恢复时间短，恢复效果好。同时，提高PLA的韧性与亲水性并且极大限度地降低其加工温度。 The invention relates to a block polymer for endowing polylactic acid (PLA) with water-induced shape memory. A main chain of the block polymer is composed of a hydroxyl-terminated vinyl polysiloxane (PMVS) block, a polytetrahydrofuran (PTMG) block and a polycaprolactone (PCL) block; and a side chain of the block polymer is polyacrylic acid (PAA). The main chain polysiloxane of the PMVS block has good flexibility, the active double bond side group of the PMVS block initiates polymerization of acrylic acid (AA), so that a PAA side chain can be obtained; and the polar carboxyl of the PAA chain segment can greatly imp