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
A series of tri\|component copolyesters composed of glycolide/lactide/caprolactone (PGLC) were obtained by bulk ring\|opening copolymerization of glycolide(GA),L\|lactide (L\|LA) and caprolactone(CL) with Sn(Oct)\-2 a...A series of tri\|component copolyesters composed of glycolide/lactide/caprolactone (PGLC) were obtained by bulk ring\|opening copolymerization of glycolide(GA),L\|lactide (L\|LA) and caprolactone(CL) with Sn(Oct)\-2 as catalyst for the purpose of biomedical applications.Structure of the PGLC copolyester was characterized by means of GPC,\{\}\+1H\|NMR,DSC and X\|ray diffractometry techniques.It was found that the obtained polymer was a pure copolymer that consisting of no other side\|produced polymers and the copolyester was a random copolymer that presented an amorphous structure in a large range of composition.The hydrophilicity and degradation rate of the copolyester were also studied in detail and it was found that the hydrophilicity and hydrolysis rate were improved by increasing the amount of GA.The mechanical properties of the PGLC copolyester were identified by measuring the tensile strength and the elongation at break.The elongation of the copolyester could be improved by introducing CL to the PLGA.That the PGLC copolyester was a potential biomedical material was suggested.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.
文摘A series of tri\|component copolyesters composed of glycolide/lactide/caprolactone (PGLC) were obtained by bulk ring\|opening copolymerization of glycolide(GA),L\|lactide (L\|LA) and caprolactone(CL) with Sn(Oct)\-2 as catalyst for the purpose of biomedical applications.Structure of the PGLC copolyester was characterized by means of GPC,\{\}\+1H\|NMR,DSC and X\|ray diffractometry techniques.It was found that the obtained polymer was a pure copolymer that consisting of no other side\|produced polymers and the copolyester was a random copolymer that presented an amorphous structure in a large range of composition.The hydrophilicity and degradation rate of the copolyester were also studied in detail and it was found that the hydrophilicity and hydrolysis rate were improved by increasing the amount of GA.The mechanical properties of the PGLC copolyester were identified by measuring the tensile strength and the elongation at break.The elongation of the copolyester could be improved by introducing CL to the PLGA.That the PGLC copolyester was a potential biomedical material was suggested.
