聚乳酸/淀粉复合材料在海水中的降解性能

摘要

Degradability of poly(lactic-acid) (PLA)/starch composite in seawater environment for 8 months was studied. The degradation of samples was estimated by gel permeation chromatography (GPC), thermogravimetry (TG) and mechanical property. The microstructure of samples was observed through SEM. The results indicate that the values of molecular weight and its' distribution of composites both decreased with the increase of time of being immersed in seawater, meanwhile thermal stability and impact strength of samples both decreased, but tensile strength and breaking elongation rate first decreased, then increased and at last decreased again. SEM photographs show that void and looseness of structure appeared in the samples with the increase of time of being immersed in seawater. The analysis showed PLA/starch composite in seawater had good degradability.%研究聚乳酸/淀粉复合材料在海水环境中历经8个月的可降解性能.对每个月取样样品的降解性能通过凝胶渗透色谱仪(GPC)、热重(TG)和力学性能进行评价,并对试样的形貌采用扫描电镜(SEM)进行观察.实验结果表明:随着在海水中降解时间的增加,样品分子量和分子量分布均逐渐减小,材料的热稳定性和冲击强度均逐渐下降,而材料的拉伸强度和断裂伸长率由于水分子的增塑作用均出现先减小后增大再减小的趋势.SEM照片显示随着降解时间的增加,材料内部逐渐出现空洞,结构变得松散.分析表明样品在海水中具有良好的降解性.