基于聚合物原位核壳粒子增韧的高性能聚丙烯合金研究

Abstract：Polymer particles with core-shell structure have been used to toughening thermoplastic resins and presents good balance between toughness and strengthen. However, the toughening mechanism and the reason of balanced toughening and strengthening are still unknown. Compared with conventional core-shell structure particles which need to be fabricated before it can be used to polymer modification, the in-situ core-shell particles in polymer alloys can be formed through continuous in-situ copolymerization or melt-blending. It is noticed that the morphology of core-shell structure particle can be accurately adjusted by melt-blending, but cannot by copolymerization method. Therefore, we plan to prepare a series of polypropylene alloys with in-situ core-shell particles by melt-blending in this proposal and investigate the microstructure, morphology and mechanical properties. As a result, the toughening mechanism and the reason of balanced toughening and strengthening in these polymer alloys will be proposed, and the quantitative relationship between structure and performance will be established. Furthermore, based on the above results, the structure and morphology of propylene alloys will be accurately adjusted by controlling chemical structure of components, composition, and preparation condition etc., and consequently the performance optimization of polypropylene alloys are achieve. Finally, a simple and efficient fabricating method of high-performance polypropylene alloys will be established.

聚合物核壳粒子在增韧热塑性树脂上表现出独特的强韧平衡特点，但是其增韧机制与强韧平衡的原因仍未揭明，相关凝聚态结构-性能定量关系也未建立。相比传统核壳粒子改性的两步法——先制备核壳母粒，后进行改性，通过反应器粒子共聚或熔融共混直接在合金材料中形成聚合物原位核壳粒子更为简单高效。与共聚方法难以实现对合金体系凝聚态结构的有效调控不同，借助熔融共混方法则可通过改变组成或制备工艺对原位核壳粒子形态进行准确调控。因此，本项目拟以熔融共混工艺制备一系列具有原位核壳粒子的聚丙烯合金，通过对其凝聚态结构与性能的系统研究，探明聚合物原位核壳粒子的增韧机理及强韧平衡机制、建立含原位核壳粒子合金材料的凝聚态结构-性能定量关系，在此基础上实现通过改变化学结构与组成、制备工艺对合金体系凝聚态结构与性能进行准确调控，从而建立一种基于原位核壳粒子的简单高效的聚丙烯高性能化新技术。同时，探索该技术对其它他通用树脂的适用性。

以聚合物原位核壳粒子改性热塑性树脂合金的结构-性能关系为核心，围绕聚合物原位核壳粒子的增韧机理、结构设计与调控、界面作用、性能优化、加工性能等开展了系统研究，形成了以原位核壳粒子增韧与强韧化技术、界面调控与低温增韧技术为主要内容的创新性成果。完善了基于等效橡胶含量与有效核壳界面应力传递的完整的聚合物核壳粒子增韧机理，建立了基于聚合物核壳粒子改性的聚丙烯增韧与强韧化技术；提出了基于组分间热膨胀系数差的脆韧转变调控方法，建立了基于连续界面构筑的界面调控与低温增韧技术，制备了兼具优异低温韧性和强韧平衡的聚丙烯合金；揭示了含原位核壳粒子热塑性合金体系的加工性能的黏弹机制，阐明了其凝聚态结构稳定性的构效关系。上述研究成果，不仅在理论上破解了一些具有特殊结构的多组分高分子合金的复杂凝聚态结构与增韧机理的重要理论问题，也为发展热塑性树脂的强韧平衡和高性能化提供了新的途径。本成果有利于促进解决上述问题，具有潜在的社会经济意义。项目执行期内，共发表SCI收录论文6篇，培养研究生5人（其中已毕业4人）。