含取向复合气体渗透屏障的高阻隔药品包装聚乳酸膜的研究

The migration of small-molecule processing aids in the polyvinyl chloride (PVC) pharmaceutical packaging not only deteriorates its performances, but also affect the safety of medicine. Referring to polymer packaging materials that replace PVC, gas barrier property is the key issue. However, traditional sing polymer films can hardly meet the demand of oxygen-sensitive medicines due to their poor gas barrier properties. Therefore, further considering the requirement of green packaging, the development of new theory and technology for preparing high barrier polymer green packaging materials has been a central issue in the field of pharmaceutical packaging. In this project, we plan to combine nanoplatelet composite technology and “extrusion-hot stretching” technology, forming well-aligned graphene oxide nanosheets (GONSs) with the aid of intense elongational flow field. The oriented row-nuclei induced by flow field and heterogeneous nucleation sites provided by well-aligned GONSs can serve as templates for poly(lactic acid) (PLA) chains to land on, thus achieving highly aligned PLA lamellae. As a result, the oriented “composite barrier wall” consisting of well-aligned GONSs and impermeable oriented PLA lamellae are highly efficient to enhance the gas barrier performance of PLA nanocomposite films. This work presented here not only provides theoretical direction for preparation of high barrier polymer green packaging materials, but also expands the application of polymer films in the field of pharmaceutical green packaging.

在聚氯乙烯（PVC）药品包装材料中，小分子加工助剂的迁移不仅影响其性能，更重要的是带来药品的安全性问题。提及替代PVC的聚合物药品包装材料，首要解决的就是气体阻隔性能。而目前，单一传统聚合物材料气体阻隔性能不足，难以满足氧气敏感性药品的包装需求。因此，结合我国药品包装“绿色”发展需求，研究聚合物气体阻隔新原理新技术，开发具有高阻隔性能的绿色环保型聚合物材料已成为药品包装产业的研究热点。本项目拟结合纳米片层填料复合技术和“熔融挤出-热拉伸”技术，利用强烈拉伸流动场诱导氧化石墨烯（GONSs）沿拉伸方向高度取向，借助拉伸流动场诱导的取向排核和取向GONSs提供的异相成核点，诱导聚乳酸（PLA）生成取向片晶结构，构建取向GONSs和取向PLA片晶组成的复合气体阻隔屏障，制备具有高阻隔性能的聚合物包装材料，为开发高阻隔绿色环保型聚合物包装材料提供理论指导，促进聚合物材料在绿色药品包装领域的应用。

针对最有希望替代石油基高分子材料的“绿色”高分子材料聚乳酸（PLA）气体阻隔性能不足的问题，本项目以无机片层纳米填料（氧化石墨烯，GONSs）、PLA晶体和高阻隔聚合物为阻隔性材料，通过高分子成型加工的结构调控，利用体积排除效应构筑三维连续非取向阻隔屏障，结合拉伸流动场构筑取向非连续阻隔屏障以及凭借多层结构设计获得连续取向阻隔屏障，从而显著改善PLA包装薄膜的气体阻隔性能。本项目凝练了制备高阻隔高分子材料的有效手段，为开发高阻隔绿色环保高分子包装材料提供理论指导，促进了高分子材料在绿色药品包装领域的应用。本项目研究过程中共发表SCI论文10篇，发表会议论文4篇，授权中国发明专利2项。培养青年教师2名，培养硕博士研究生8名（博士4名、硕士4名），其中已毕业6名，在读2名。获四川省科学技术进步奖（自然科学类）二等奖学术荣誉。