PLA/PBAu嵌段共聚物合成工艺优化及降解性能

Synthesis process optimization and degradation properties of PLA/PBAu block copolymer

以端羟基聚乳酸(PLA)、聚己二酸-丁二醇-尿素(PBAu)为预聚物,六亚甲基二异氰酸酯(HDI)为扩链剂,制备出一种新型PLA/PBAu嵌段共聚物。研究了扩链剂用量、扩链温度以及催化剂用量对PLA/PBAu嵌段共聚物分子量的影响,确定了合成PLA/PBAu嵌段共聚物的最佳工艺条件。采用核磁共振、凝胶渗透色谱、差示扫描量热仪、扫描电镜等对共聚物薄膜结构及性能进行表征。结果表明:成功合成了PLA/PBAu嵌段共聚物,分子量可达10×10~4,玻璃化转变温度约为41℃;并且随着PBAu含量的增加,共聚物的结晶度逐渐增加。以NaOH溶液为模拟液进行加速降解实验发现,当PBAu含量为30%时,可以显著提高嵌段共聚物的降解速率,并且通过调节PLA、PBAu预聚物的含量,可以控制嵌段共聚物的降解速率。

A novel PLA/PBAu block copolymer was synthesized by using the hydroxyl terminated poly(lactic acid)(PLA)and poly(butyl acrylate urea)(PBAu)as prepolymer and the hexamethylene diisocyanate(HDI)as chain extender.To determine the optimum synthesis condition for the chain extension,the effects of the amount of chain extender,the chain extension temperature and the amount of catalyst on the PLA/PBAu block copolymer molecular weight were studied.The structure and properties of the films were studied by nuclear magnetic resonance,gel permeation chromatograph,differential scanning calorimetry and scanning electron microscope.The results showed that the PLA/PBAu block copolymer was successfully synthesized,and the molecular weight of the copolymer can reach to 105 with glass transition temperature of 41℃.The crystallization of copolymer films increased with the increase of PBAu content.The accelerated degradation experiment of block copolymers was studied with NaOH solution as the degradation solution.The results showed the degradation rate of copolymer can be significantly improved when the content of PBAu was 30%.The degradation rate of block copolymer could be controlled by adjusting the content of PLA and PBAu prepolymer.