己内酯/乙交酯嵌段共聚物的合成及水解行为研究

摘要

以辛酸亚锡为催化剂,合成了己内酯预聚物(PCL),再与乙交酯(GA)熔融共聚,制备了嵌段型己内酯乙交酯共聚物(PCL/GA).利用GPC、FT-IR、1 H-NMR和13C-NMR等对PCL/GA的结构进行了表征,确认合成的共聚物为嵌段型聚酯共聚物.利用XRD和DSC测试了PCL/GA的结晶状态和热学性能,测试发现合成的共聚物均为结晶型聚合物,且结晶情况与单体组成有关,利用石英微晶天平考察了PCL/GA(80/20)在海水中的水解行为,发现前3h聚酯降解速率波动较大,推断是由于初期嵌段聚酯吸水与降解作用同时进行所致,随着吸水作用的完成,后期嵌段聚酯的降解速率维持在80 ng/(cm2 ·h)左右,降解速率稳定.利用POM、SEM观察了水解过程中薄膜结晶及形貌变化.%With stannous octoate as a catalyst, caprolactone prepolymers( PCL) was synthesized, which was then melten copolymerized with glycolide( GA) to prepare the block copolymer of caprolactone glycolide (PCL/GA). The structure of the PCL/GA were characterized by GPC, FT - IR, 1H - NMR and 13C -NMR, confirming the block structure of the copolymer. The crystallization state and thermal properties of the PCL/GA was tested by XRD and DSC. It was found that all the prepared copolymers were crystalline polymers and the crystallization behavior was related with monomer composition. The hydrolysis behavior of the PCL/GA(80/20) in seawater was investigated by use of QCM - D. It was found that the hydrolysis rate of the polyester fluctuated in the first three hours, which was inferred due to the simultaneous absorbent and hydrolysis of the polyerter at initial stage. With the completion of the water absorption, the hydrolysis rate of the block polyester was maintained at about 80 ng/(cm2·h) stably. Crystallinity and the morphology changes of the film in the hydrolysis process was characterizationed by POM and SEM.