论文部分内容阅读
采用己二醇对聚丁二酸丁二醇酯(PBS)改性,合成了不同比例、分子质量均在6×105左右的聚丁二酸丁二醇/己二醇酯(PBSH),并以其为底物分别在2种不同的有机溶剂氯仿(CHCl3)和四氢呋喃(THF)中,研究了洋葱假单胞菌(PC)脂肪酶对其催化降解规律和溶剂效应。以GPC测试了共聚物降解前后的分子质量变化;以TG分析了酶降解共聚物前后热性能的变化;以MALDI-TOF-MS对降解产物进行了分析。研究结果表明:PBSH在2种溶剂中都能快速降解;降解60 h后2种共聚物的相对分子质量均减小,分子质量分布均变宽;但在氯仿中酶催化活性更高,PBSH降解速率更快;降解前后热失重5%时热分解温度均降低;MALDI-TOF-MS结果表明:在2种溶剂中降解产物中含SH(丁二酸己二醇酯)片段较多,且氯仿中降解产物种类更多,并易于成环。
Polybutylene succinate (PBS) was modified with hexylene glycol to synthesize polybutylene succinate / hexylene glycol (PBSH) with different ratios and molecular weights of about 6 × 105 The catalytic degradation and solvent effects of Pseudomonas cepacia (PC) lipase were investigated in two different organic solvents, chloroform (CHCl3) and tetrahydrofuran (THF), respectively. The changes of molecular mass before and after the degradation of the copolymer were measured by GPC. The changes of thermal properties before and after degradation of the copolymer by TG were analyzed. The degradation products were analyzed by MALDI-TOF-MS. The results showed that PBSH degraded rapidly in both solvents. After 60 h degradation, the relative molecular mass of the two copolymers decreased and their molecular mass distribution broadened. However, the activity of the enzyme in chloroform was higher than that of PBSH The results showed that the degradation products contained SH (succinate adipate) fragments in more than two solvents, and chloroform More types of degradation products, and easy to loop.