离子液体聚合物界面增容改性聚乳酸-天然高分子复合材料机理与性能研究

Green composite from biomass-based fiber/Polylactide( PLA) is a kind of full eco-friendly material. Wide use of these composites will make a great contribution for the sustainable development of economy and society. Improving the poor miscibility of the biofiber and PLA to enhance the performance plays a key role on development of the composites. In this project, a series of novel poly(ionic liquid) (PIL) copolymers will be designed and synthesized to be used as compatibilizers for the biomass-based fiber and PLA. Green composites of the biofibre, PLA and PIL will be fabricated through melt blending method. The relationship of the chain structure of PIL with the interaction and miscibility of the components will be figured out by thoroughly study of the phase structure, interphase and physical properties of the composites. On the basis of these results, the modifying mechanisms behind the improved compatibility and performance of the composites will be established. These fundamental researches will be greatly helpful for the development of the high performance biocomposites, which will find wide application in high-value area.

天然纤维/聚乳酸(PLA)基复合材料是一类完全生物友好材料，其广泛应用对社会和经济的可持续发展具有十分重要的意义。有效改善天然纤维与聚乳酸的相容性，从而赋予材料优良的综合性能是复合材料发展的关键。基于此，本项目拟设计合成一系列新型的离子液体共聚物（PIL-Copolymer）作为不同尺度秸秆纤维与PLA的界面增容改性剂，利用熔融共混构造高性能复合材料。通过研究不同结构离子液体共聚物对PLA/纤维素复合体系相容性、相形态及界面结构、物理性能和熔融过程的影响，深入研究链结构-组分间相互作用-相容性之间关系，揭示离子液体共聚物对秸秆纤维与PLA的相结构、界面作用和物理性能的调控改性内在机理。进而利用离子液体聚合物实现对PLA/秸秆纤维复合材料的高效增容改性，赋予材料优良的性能，促进材料在高附加值领域的应用。

本项目面向高分子材料导致的环境污染与能源问题，聚焦国家绿色可持续发展重大需求，以构造高性能聚乳酸基材料为目标，通过设计合成一系列新型含离子基团的离聚物弹性为聚乳酸及其秸秆纤维复合材料的增容/增韧改性剂，实现聚乳酸材料的低成本高性能化，从而促进其在广泛领域的应用。基于以上目标与思路，本项目首先设计合成了一系列结构不同的咪唑单体，通过该类单体与含卤素基团的弹性体（溴丁基橡胶、氯醚橡胶和新型聚烯烃类弹性体）季胺化反应，获得一系列性能均衡的离聚物弹性体，并应用于聚乳酸共混改性体系，实现了高韧、高透明聚乳酸基材料的制备。进而，通过对离聚物结构与共混体系相容性、相结构和物理性能的之间关系的分析，揭示离聚物弹性体改性聚乳酸多元体系的影响规律，指导高性能低成本聚乳酸-离聚物-秸秆纤维多元复合材料的开发与研究。