【摘要】 以L-丙交酯、乙交酯和ε-己内酯为原料开环聚合合成了不同组成比例的三元共聚物(PLLGC)。研究了PLLGC在人工肠液、37℃条件下一个月内的体外降解行为。采用GPC、1 H-NMR、DSC、SEM和万能拉力机研究了聚合物在降解过程中分子量及分子量分布、分子组成、热性能、表面形貌和力学性能的变化。由聚合物分子组成变化知PGA链段易于降解,PCL链段不易降解。由降解过程中聚合物分子量的变化和质量损失知在降解15天后主要是分子链的断裂,而在15-30天内才有小分子的溶出,一个月后的质量损失为15-40%。由DSC测试结果知降解30天后玻璃化转变温度由55℃降到34℃,并伴随有结晶现象的出现。由降解过程中拉伸强度的变化知,在降解10天内拉伸强度下降缓慢,具有力学稳定性,降解30天后,拉伸强度迅速从64-65 MPa下降到35-37MPa。更多还原

【Abstract】 A series of poly(L-lactide-co-glycolide-co-ε-caprolactone)(PLLGC)were synthesized by ring-opening polymerization with L-lactide(L-LA),glycolide(GA)andε-caprolactone(ε-CL).The degradation behavior of PLLGC was investigated in simulated intestinal fluid at 37 ℃in vitro within a month.The changes of molecular weight,molecular weight distribution,composition of the polymer,thermal properties,surface morphology and mechanical properties were researched by GPC,1 H-NMR,DSC,SEM and tensile strength.The PCL component appears the most resistant to degradation,and the PGA,the most degradable according to compositional changes. The changes of the molecular weight and mass loss of the terpolymers during degradation tell us that the molecular weight decrease rapidly in the 15days’ degradation and the soluble oligomers release from the bulk sample after 15 days’ degradation,and the mass loss was about 15%-40%after 30days’ degradation.The DSC results show that the Tg decreases from 55℃to 34℃,and the melting peak appeared in DSC curves after 30days’ degradation.The changes of the tensile strength during degradation show that the tensile strength decrease slowly in 10days’ degradation with good mechanical stability,and decrease from 64-65 MPa to 35-37 MPa after 30days’ degradation.更多还原