论文部分内容阅读
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。
Different proportions of ternary copolymer (PLLGC) were synthesized by ring-opening polymerization of L-lactide, glycolide and ε-caprolactone. The in vitro degradation behavior of PLLGC in artificial intestinal juice at 37 ℃ for one month was studied. The molecular weight, molecular weight distribution, molecular composition, thermal properties, surface topography and mechanical properties of the polymer were studied by GPC, 1 H-NMR, DSC, SEM and universal tensile tester. Changes in the composition of the polymer molecules know PGA segments easy degradation, PCL segments are not easily degraded. From the change of the molecular weight and the loss of mass of the polymer in the process of degradation, it is mainly the break of the molecular chain after 15 days of degradation that the dissolution of small molecules occurs within 15-30 days and the mass loss after one month is 15-40%. From the DSC test results, the glass transition temperature was lowered from 55 ° C to 34 ° C after 30 days of degradation, accompanied by the appearance of crystallization. According to the change of tensile strength during degradation, the tensile strength decreased slowly within 10 days of degradation, with mechanical stability. After 30 days of degradation, the tensile strength rapidly decreased from 64-65 MPa to 35-37 MPa.