摘要
以N-(苄氧羰基)-L-天冬氨酸和亚硫酰氯反应制备了N-苄氧基天冬氨酸酐,然后将其与不同链长的二醇(Diol:乙二醇、二缩三乙二醇、聚乙二醇200和600)缩聚,合成含端羟基的天冬氨酸-二醇交替预聚物[ASP-Diol];分别以它们为大分子引发剂,辛酸亚锡为催化剂进行丙交酯/乙交酯(LA/GA:75/25)开环共聚,合成系列含侧氨基的天冬氨酸-二醇-聚乙丙交酯[PLGA-(ASP-Diol)-PLGA]多元三嵌段共聚物。利用FTIR、1HNMR、EA、DSC和GPC对共聚物结构进行了表征。结果表明,影响预聚物分子量的主要因素不是二醇的分子量,而是其端羟基的活性。但随着二醇链段长度增加,多元共聚物中氨基含量降低,玻璃化温度也明显下降。因此,通过改变二醇链段的长度(或分子量)可以有效控制PLGA-(ASP-Diol)-PLGA中侧氨基的密度及分布。
A series of poly （ASP-Diol） s were first prepared by polycondensation reactions of N-CBz-L-asparfie acid anhydride with different molecular weight of diols including ethylene glycol, triethylene glycol, PEG200 and PEG600, respectively. The synthesized poly （ASP-Diol） s were used as macromonomer initiators respectively to synthesize biodegradable copolymers PLGA- （ASP-Diol） -PLGAs having different contents of pendant amino groups by ring-opening copolymerization of lactide/glycolide （75/25）. Their structures were confirmed by 1H NMR, FTIR, EA, DSC and GPC. Results indicated that the main factor that affects the molecular weights of the prepolymers is not the molecular weights of diols, but the activity of the end hydroxyl groups. With increasing the chain length of the diols, the content of amino groups in the copelymers decreased, and the glass translation temperature （Tg） decreased obviously; therefore, it is considered that the .content and distribution of amino groups in the copolymers can be effectively adjusted by changing the chain length of the diols.
出处
《中山大学研究生学刊（自然科学与医学版）》
2006年第2期52-59,共8页
Journal of the Graduates Sun YAT-SEN University(Natural Sciences.Medicine)
关键词
天冬氨酸
聚乳酸
聚乙醇酸
聚乙二醇
N-CBz-L-aspartic acid
poly （lactie acid）
poly （glycol acid）
polyethylene glycol
