成核剂TCP和增塑剂PLLCA82/18对PLLGA85/15结晶性能和降解性能的影响

Influence of nucleating agent TCP and plasticizer PLLCA82/18 on degree of crystallinity and degradation property of PLLGA85/15

选择磷酸三钙(TCP)为成核剂、左旋乳酸己内酯无规共聚物(PLLCA82/18)为增塑剂加入到左旋乳酸乙醇酸无规共聚物(PLLGA85/15)中,用平板硫化机热压成薄片,在130℃等温退火40min。通过万能力学实验机测试材料的力学性能,通过X射线衍射仪考察复合材料的结晶情况。结果表明:只需添加1%TCP和2%PLLCA82/18,复合材料的结晶度和拉伸强度即可得到显著改善,并且材料内部无明显缺陷产生。对复合材料进行降解实验,考察了降解过程中样品失重率和降解液pH的变化,通过扫描电镜观察降解后样品的微观形貌变化情况。降解实验结果表明复合材料的降解速率减缓,退火后材料的降解速率均加快。

Tricalcium phosphate(TCP) was used as nucleating agent and poly(L-lactic acid-co-ε-caprolactone) with monomer molar ratios of 82/18(PLLCA82/18) was used as plasticizer, they were added into poly(L-lactic-co-glycolic acid) with monomer molar ratios of 85/15(PLLCA85/15) simultaneously to improve its degree of crystallinity.Then the composite samples were isothermal annealed at 130℃ for 40 min.The mechanical properties were tested, and the degree of crystallinity was investigated by XRD.The results shown that the crystallinity and tensile strength of the composites were significantly improved.The in vitro degradation properties were studied by investigating the mass loss of the samples and the pH of the degradation solution.The morphology of the degraded samples was observed by SEM.The results indicated that the degradation rate of the composite samples was slower than that of PLLGA85/15,and the degradation rate was faster after annealing.