铋/锡催化L-丙交酯与乙交酯本体开环共聚

Bulk Ring-Opening Copolymerization of L-Lactide and Glycolide Catalyzed by Bismuth/Tin

为探究金属催化剂辛酸亚锡(Sn(Oct)_(2))与次水杨酸铋(BiSS)对L-丙交酯(L-LA)与乙交酯(GA)本体开环聚合(ROP)反应过程及产物性能的影响,使用不同含量的Sn(Oct)_(2)或BiSS合成一系列聚丙交酯-乙交酯共聚物(PLGA)。通过核磁共振波谱仪、傅里叶变换红外光谱仪、凝胶渗透色谱仪对聚合物的微观结构、聚合反应动力学和相对分子质量进行了表征,借助热重分析仪和差示扫描量热仪对聚合物的热性能进行了分析。结果表明,BiSS是一种非常有吸引力的催化剂,在ROP制备PLGA共聚物中获得了与Sn(Oct)_(2)类似的结果,其催化性能可与Sn(Oct)_(2)相媲美。BiSS催化制备的PLGA的热稳定性显著提高,例如,1000×10^(-6)Bi催化制备的PLGA73在氮气氛围下的T_(5)%和T_(90)%分别为269.6℃和379.2℃,相较于Sn(Oct)_(2)分别升高了36℃和82.7℃。由BiSS催化制备的PLGA链段具有更高的随机性和更短的L-LA序列长度。BiSS可以替代商业使用的Sn(Oct)_(2)用于生产生物医学领域应用的低毒性PLGA。

To investigate the effects of metal catalysts Sn(Oct)_(2)and bismuth salicylate(BiSS)on the reaction process and product properties of bulk ring opening polymerization(ROP)of L-lactide(L-LA)and glycolide(GA),a series of polylactide glycolide copolymers(PLGA)were synthesized using different amounts of Sn(Oct)_(2)or BiSS.The microstructure,polymerization kinetics and molecular weight of the polymer were characterized by NMR,FT-IR and gel permeation chromatography.The thermal stability of the polymer was analyzed by thermogravimetry and differential scanning calorimetry.The results show that BiSS is a very attractive catalyst,and its catalytic performance similar results are comparable to that of Sn(Oct)_(2)in the preparation of PLGA.The thermal stability of PLGA prepared with BiSS catalysis is significantly improved.For example,the T_(5%)and T_(90%)of PLGA73 prepared with 1000×10^(-6)Bi catalysis in nitrogen atmosphere are 269.6℃and 379.2℃,respectively,which are increased by 36℃and 82.7℃compared to those of Sn(Oct)_(2),respectively.The PLGA segments prepared with BiSS catalysis exhibit higher randomness and shorter L-LA sequence length.BiSS can replace commercially used Sn(Oct)_(2)for the production of low toxicity PLGAs for biomedical applications.