表面引发不朽聚合反应制备CO2聚碳酸酯纳米复合材料的研究

The synthesis of polycarbonates using CO2 as C1 source has become an important research field in the environmental-friendly and biodegradable polymer science. However, amorphous polycarbonates show too low mechanical properties to extend their applications. The various inorganic nanoparticles have been typically added to polymer matrix to improve physical and mechanical properties so as to more functionality. In this project, by means of the surface-initiated immortal polymerization, active groups (-OH, -COOH) on the surface of the nanoparticles can directly initiate CO2 and epoxides alternating polymerization for grafting modification, terpolymerization and block polymerization in the catalytic system of metal complexes; The amorphous and crystalline polycarbonates nanocomposites are synthesized via in situ surface-initiated immortal polymerization.High grafting degree for the nanoparticles in the polycarbonate nanocomposite can be easily to achieve to improve stronger interfacial interaction with polymer matrix, and gain uniform dispersion in the polymer matrix; The reaction condition, microstructure, macroscopic mechanical properties and their relations will be studied in order to provide a novel route and methodology for the fabrication and design of CO2 polycarbonate nanocomposite with high performance and multi-fuctionality.

CO2作为碳源构筑的聚碳酸酯是环境友好生物可降解性高分子的重要组成部分，然而其较低的力学性能限制了它的广泛应用。将无机纳米材料引入高分子基体中则可显著提高聚合物的物理性能和机械性能，并赋予聚合物更多功能。本项目利用绿色的"表面引发不朽聚合"新方法，即在金属配合物作用下，纳米粒子表面活性基团（-OH,-COOH）直接引发CO2和环氧化合物交替共聚进行接枝改性，并制备表面引发三元共聚和嵌段共聚；利用表面引发不朽聚合方法原位制备无定形和结晶性聚碳酸酯纳米复合材料，通过制备高接枝率纳米粒子，增强纳米粒子与聚合物的界面结合力，实现纳米粒子以纳米尺度均匀分散；研究反应条件、微观结构、宏观力学性能以及三者之间关系，为制备高性能的、多功能的二氧化碳聚碳酸酯纳米复合材料提供新思路和新方法。

将无机纳米材料引入高分子基体中则可显著提高聚合物的物理性能和机械性能，并赋予聚合物更多功能。本项目利用"表面引发不朽聚合"新方法，实现了硅胶、碳纳米管及金表面活性基团（-OH,-COOH）直接引发二氧化碳和环氧化合物交替共聚进行接枝改性原位制备了聚碳酸酯纳米复合材料。通过分析测试发现，聚碳酸酯/硅胶纳米复合材料不仅提高了硅胶在有机溶剂中的溶解性和分散性，同时也改善了聚碳酸酯的耐热性和力学性能；聚碳酸酯功能化的碳纳米管可以很好地溶解于极性或者非极性的有机溶剂中，并展示出非常优异的机械强度（复合材料的抗拉强度、断裂伸长量以及杨氏模量增大）及导电性；接枝有聚碳酸酯刷的金具有良好的抗蛋白非特异吸附性。除此之外还实现了Lewis酸碱对聚合制备基于极性烯烃单体和丙交酯的嵌段共聚物，双金属铬配合物催化内酯、酸酐和二氧化碳与环氧烷烃共聚及三元共聚反应合成聚酯及聚碳酸酯，双金属钴配合物催化羰基硫与环氧烷烃的高立体选择性交替共聚反应合成手性含硫聚单硫代碳酸酯。