Poly(lactic acid) (PLA) is the most used biodegradable polymer derived from renewable resources. However, PLA is a brittle plastic with low resistance to fracture. In this study, we tried to increase flexibility and hydrophobicity by melt-blending it with octadecenylsuccinic anhydride (ODSA) which was synthesized by reaction of octadecene and maleic anhydride. After mixing, thermal and mechanical properties of the PLA/ODSA blends (100/5, 100/10, 100/15) were measured. The results showed that at low contents of ODSA, the PLA was miscible with ODSA, and the PLA/ODSA blends had higher hydrophobicity than the neat PLA. The water contact angle of the PLA/ODSA (100/15) reached a value of 95.9°. Moreover, The addition of ODSA decreased the glass transition temperature and crystallization temperature, producing most α′ crystals during crystallization and therefore resulting in the observed exotherm in DSC curves owing to the α′-to-α crystal transformation. Most importantly, the flexibility was improved as the elongation at break increased from 3.1% for the PLA to 15.1% for the PLA/ODSA blend (100/10), in which stress-whitening was observed during tensile testing. The biodegradability of the PLA/ODSA blends was tested using proteinase K, and the results showed the addition of ODSA did not affect the enzymatic degradability of the PLA.

聚乳酸（PLA）是衍生自可再生资源的最常用的可生物降解聚合物。但是，PLA是一种脆性塑料，具有较低的抗断裂性。在这项研究中，我们试图通过与十八碳烯基琥珀酸酐（ODSA）熔融共混来增加柔韧性和疏水性，十八碳烯基琥珀酸酐是由十八碳烯和马来酸酐反应合成的。混合后，测量PLA / ODSA共混物（100 / 5、100 / 10、100 / 15）的热和机械性能。结果表明，ODSA含量低时，PLA与ODSA可混溶，并且PLA / ODSA共混物的疏水性比纯PLA高。PLA / ODSA的水接触角（100/15）达到95.9°。此外，添加ODSA降低了玻璃化转变温度和结晶温度，在结晶过程中会产生大多数α'晶体，因此由于α'到α的晶体转化，导致在DSC曲线中观察到放热。最重要的是，当断裂伸长率从PLA的3.1％增加到PLA / ODSA共混物（100/10）的15.1％时，柔韧性得到了改善，在拉伸试验中观察到了应力白化。使用蛋白酶K测试了PLA / ODSA共混物的生物降解性，结果表明添加ODSA不会影响PLA的酶促降解性。