目的 制备具有优异阻隔性能及热稳定性的聚乳酸薄膜材料。方法 在聚乳酸中添加石墨烯对其进行改性。首先采用改进的Hummers法将鳞片状石墨制备成氧化石墨烯， 继而采用热剥离法将氧化石墨烯还原剥离为石墨烯， 然后以聚乳酸为基材， 还原后的石墨烯为增强相， 采用流延法制备石墨烯/聚乳酸复合薄膜， 并测试了其结构、 热稳定性以及阻隔性能。结果 红外分析表明， 石墨被强氧化剂氧化后形成了以C—OH， —COOH， C—O—C和C＝O等官能团形式存在的石墨层间化合物， 还原后获得的石墨烯剥离充分； 石墨烯/聚乳酸复合薄膜的热稳定性能和阻隔性能随石墨烯含量的增加而逐渐增强。结论 在试验参数范围内， 石墨烯/聚乳酸复合薄膜的热稳定性和阻隔性能优于聚乳酸薄膜。

This work was aimed to obtain polylactic acid films with good barrier properties and thermal stability. Graphene was added into polylactic acid to modify it. Graphene oxide was prepared using the flaky graphite by the improved Hummers method. Graphene oxide was reduced to graphene by thermal stripping method. Grapheme/ polylactic acid films were prepared with tape casting method, using polylactic acid as the substrate and graphene as the reinforcement. The structure, thermal stability and barrier properties of films were tested. Infra-red spectrogram showed that graphite intercalation compound with COOH, C＝O, C—O—C and C—OH functional groups was formed when graphite was oxidized by the strong oxidizer, and graphene stripped sufficiently by reduction. The thermal stability performance and barrier properties of graphene and lactic acid composite films increased with the increasing graphene content. Within the scope of the test parameters, the thermal stability and barrier performance of the graphene/PLA composite films were better than those of polylactic acid film.