对提高可生物降解聚酯PBS相对分子质量影响因素的研究

STUDY ON THE FACTORS FOR IMPROVING MOLECULAR WEIGHT OF BIODEGRADABLE POLY(BUTYLENES SUCCINATE)(PBS)

采用双催化剂,由对丁二酸(Succinic Acid)和1,4-丁二醇(Butanediol)缩聚得到了高相对分子质量的PBS(Poly(butylenes succinate))。就反应温度、催化剂用量、反应时间和双催化剂的配比等因素对PBS相对分子质量的影响进行了研究,利用凝胶色谱分析测定了聚合物的相对分子质量,利用核磁共振分析鉴定了聚合物的化学结构,利用热分析仪测定了聚合物的热性质。结果表明:采用双催化剂可在较短的时间内得到数均相对分子质量达6万以上,相对分子质量分布2左右的PBS。最佳反应条件为:反应温度230℃,催化剂用量0.115 mmol,反应时间2 h左右。与单独加入四异丙氧基钛催化剂相比,加入适量的磷酸作助催化剂可以缩短反应时间,提高PBS的相对分子质量。

Using the biscatalyst, we prepared the high molecular weight poly（butylenes succinate） PBS by the polycondensation of succinic acid and 1,4-butanediol. In order to improve the molecular, we studied the factors such as reaction temperature, catalyst amount, reaction time and biscatalyst molar ratio P/Ti. The characters such as molecular weight, chemical structures and thermal properties of polymers were characterized by GPC （gel permeation chromatography）, NMR （nuclear magnetic resonance）, DSC （differential scanning calorimetry） and TG （thermogravimetry）. The data of GPC showed that the Mn of the polymers is more than 6.0×10^4 and the molecular weight distributions were less than 2.0. We deduced the optimal condition of preparing PBS. reaction temperature is 230℃, catalyst amount is 0. 115 mmol and reaction time about 2h. Compared with only hsing TTP, the molecular weight of PBS can improve and remarkably decrease the synthesis time when phosphorus compound added.