三亚甲基碳酸酯-丙交酯-乙交酯三元共聚物的合成与性能表征

以辛酸亚锡为催化剂,采用开环聚合制备了高分子量的三亚甲基碳酸酯-丙交酯二元共聚物(PTLA)和三亚甲基碳酸酯-丙交酯-乙交酯三元共聚物(PTLGA).所有聚合物样品的数均分子量均在105以上,分子量分布指数n介于1.4～1.9.通过合成方法的控制,制备的PTLA和PTLGA具有无规序列结构.与PLLA和PTLA相比,GA单元的引入使得聚合物的结晶能力下降,PTLGA具有更低的熔点和结晶度.在力学性能测试中,三种聚合物材料的拉伸强度均高于47MPa.然而,PTLGA的拉伸断裂功为1.0×105 kJ·m-3,远高于PLLA与PTLA的断裂功(约2.0×104 kJ·m-3),表明PTLGA的拉伸韧性大幅提高.血小板粘附实验显示PTLGA对血小板的激活程度小,具有更好的血液相容性.因此PTLGA是一种新型生物可降解聚合物血管支架材料.

Synthesis and Properties of Trimethylene Carbonate-L-Lactide-Glycolide Terpolymers

A series of high molecular weight polymers were prepared by ring-opening polymerization of L-lactide(L-LA),1,3-trimethylene carbonate(TMC) and glycolide(GA) using stannous octoate as catalyst.The molecular weights of the obtained polymers are all above 105,and the polydispersity index is between 1.4—1.9.The polymers exhibit random chain structures.Due to incorporation of GA units,the melting point and crystallinity of PTMC-LLA-GA(PTLGA) are lower than those of PTMC-LLA(PTLA) and PLLA.In the tensile tests,the ultimate tensile strengths of the polymers are all above 47 MPa.PTLGA exhibits the highest toughness with energy to break of 1.0×105kJ·m-3,whereas other polymers appear brittle with energy to break about 2.0×104kJ·m-3.Moreover,the low activation of platelets on the surface of PTLGA indicate good haemolytic properties.Therefore,it is concluded that PTLGA is promising candidate materials as biodegradable stent material.