改性淀粉/聚乳酸共聚物的生物降解性研究

The Biodegradability of Modified Starch Grafting Polylactic Acid

采用原位接枝共聚法合成了改性淀粉/聚乳酸接枝共聚物。考察了3种改性剂对淀粉改性处理结果,探讨了改性淀粉接枝聚乳酸的共聚反应机理,用凝胶渗透色谱-多角度激光光散射联用仪(SEC/MALLS)、红外光谱仪(IR)和差示扫描量热仪(DSC)对共聚物结构进行表征,测试了共聚物的降解性能。结果表明,马来酸酐的改性效果最好,并成功合成了改性淀粉接枝聚乳酸共聚物,SEC/MALLS测得共聚物的相对分子质量Mw为6.921×104,Mn为4.789×104,相对分子质量分布Mw/Mn为1.445。降解实验结果为,在PBS中淀粉/聚乳酸共聚物降解速率较聚乳酸更快。

In this study,a modified starch-g-polylactic acid was synthesized by in situ graft copolymerization.Three modifiers were analyzed in modifying soluble starch,and the copolymerization mechanism was discussed preliminarily.The copolymer was characterized by IR,（H^1-NMR） and SEC/MALLS.It is concluded that maleic anhydride was the best modifier,contributing to starch grafting with PLA;molecular weight（Mw）of the copolymer is to be 6.921×10^4,molecular weight distribution（Mw/Mn） 1.445.In addition,the degradation study showed that mass of the copolymer degraded faster than that of PLA in PBS buffer solution.