用扫描电子显微镜对聚苯乙烯 b 聚丙烯酸 (PS b PAA)嵌段共聚物在水中自组装形貌进行了观察。结果表明 :外界环境和制样方法能够影响聚合物的自组装和聚集情况。 0℃时 ,PS38 b PAA2 10 胶束聚集形成纺锤状结构。而在临界条件下 ,缓慢...用扫描电子显微镜对聚苯乙烯 b 聚丙烯酸 (PS b PAA)嵌段共聚物在水中自组装形貌进行了观察。结果表明 :外界环境和制样方法能够影响聚合物的自组装和聚集情况。 0℃时 ,PS38 b PAA2 10 胶束聚集形成纺锤状结构。而在临界条件下 ,缓慢改变体系冷冻 解冻循环次数 ,则会得到这些纺锤结构的花状聚集体。展开更多
A series of multiblock copolymers of PLLA\|PEG(PLE) with high molecular weight were synthesized by coupling PLLA\|PEG\|PLLA triblock copolymers with succinic anhydride in the presence of ( N,N\| dimethylamino) pyridin...A series of multiblock copolymers of PLLA\|PEG(PLE) with high molecular weight were synthesized by coupling PLLA\|PEG\|PLLA triblock copolymers with succinic anhydride in the presence of ( N,N\| dimethylamino) pyridine(DMAP) and dicyclohexylcarbodimide (DCC).The results of the viscometry measurement,GPC and 1H\|NMR,elucidated that multiblock PLE copolymers with high content of short PEG segments( M n=2000) had been successfully obtained.The crystallinity of the copolymers was investigated by X\|ray diffraction.Mechanical testing showed that multiblock copolymers had relatively high tensile strength and large elongation.In a word,the measurements showed that the multiblock PLE copolymers had high content of short PEG segments( M n=2000),high molecular weight( M w～100,000),excellent hydrophilicity and mechanical properties.The results of cells cultured on the multiblock PLE copolymer indicated that it might be suitable to be utilized as cell scaffold for tissue engineering.展开更多
文摘A series of multiblock copolymers of PLLA\|PEG(PLE) with high molecular weight were synthesized by coupling PLLA\|PEG\|PLLA triblock copolymers with succinic anhydride in the presence of ( N,N\| dimethylamino) pyridine(DMAP) and dicyclohexylcarbodimide (DCC).The results of the viscometry measurement,GPC and 1H\|NMR,elucidated that multiblock PLE copolymers with high content of short PEG segments( M n=2000) had been successfully obtained.The crystallinity of the copolymers was investigated by X\|ray diffraction.Mechanical testing showed that multiblock copolymers had relatively high tensile strength and large elongation.In a word,the measurements showed that the multiblock PLE copolymers had high content of short PEG segments( M n=2000),high molecular weight( M w～100,000),excellent hydrophilicity and mechanical properties.The results of cells cultured on the multiblock PLE copolymer indicated that it might be suitable to be utilized as cell scaffold for tissue engineering.
