离子液体催化合成聚碳酸酯反应过程及产品结构调控机制

Developing a cleaning process for the copolymerization of epoxide and CO2 to produce poly(carbonate) is an important direction in the technological development, substituting for the synthesis of poly(carbonate) via traditional phosgene method. The disadvantages of current catalysts such as complicated structure, high cost and low temperature applicability, lead to develop new kinds of catalysts. Based on the unique physical and chemical properties of ionic liquids, such as structure controllable, acid/base adjustable and component compatible, the investigation on the polycarbonate synthesis process catalyzed by Lewis acid-base ionic liquid is carried out. First, Lewis acidity/basicity and structure optimization of ionic liquids are realized via molecular simulation and computer calculation based on the ionic liquid hydrogen-bond network structure. Second, 2-3 kinds of Lewis acid-base complex ionic liquids are synthesized, in which, the cations are selected from a hydroxyl group or an amino-substituted imidazole, triazole and tetrazole heterocyclic compound, and the anions are aluminum, zinc, and tin multi-nuclear halides. Third, to obtain the effect laws of spatial structure of the cation and anion, substituent electronic effects, hydrogen bond network structure of product regioselectivity, molecular weight distribution and synthesis kinetics; Finally, by means of electrospray ionization mass spectrometrymass, NMR, in situ FT-IR and computer simulation reveals the copolymerization reaction mechanism,developing a new ionic liquids catalytic system, obtaining a new method on tailoring poly(carbonate) structure, and revealing the ionic liquids synergistic catalytic mechanism.The above research aims to provide the scientific basis for the technology development of ionic liquids catalytic synthesis of poly(carbonate).

替代传统光气与二醇缩聚法，建立环氧烷烃与CO2共聚合成聚碳酸酯清洁工艺是聚碳酸酯领域技术发展的重要方向。针对现有研究催化体系结构复杂、成本高、适用性有限，离子液体研究不足等问题，结合离子液体结构可控、酸碱可调及多位点活化等独特性质，本项目拟开展离子液体催化CO2共聚合成聚碳酸酯反应过程及调控研究：以脂环族环氧环己烷，脂链族端位供电子环氧丙烷、端位吸电子环氧氯丙烷为模拟底物，设计合成2-3类铝、锌、锡等金属复配型（季铵、咪唑、三氮唑、四氮唑）离子液体，采用电喷雾质谱、核磁共振、原位红外及量化计算等手段，获取反应底物、离子液体路易斯酸碱性、阴阳离子空间结构、配位离去能力、取代基及氢键结构等对产物、结构、区域及立体选择性影响规律，基于反应动力学、热力学数据，构建离子液体催化新体系，获得聚碳酸酯结构调控新方法，揭示离子液体正负协同催化调控机理，为离子液体催化合成聚碳酸酯酯工艺技术发展提供科学基础。

聚碳酸酯（PC）是我国用量最大的热塑性工程塑料，市场前景广阔，但技术落后，亟需升级换代。替代传统光气法，发展以离子液体为催化介质的聚碳酸酯清洁合成工艺是聚碳领域技术发展的一个重要研究方向。针对现有工艺中催化体系结构复杂、产品生物毒性等问题，本项目通过新型离子液体催化剂的研发，发展了高效清洁的聚碳酸酯合成新技术，并提高了产品的聚合度和热力学等性能。项目的主要研究内容包括：设计合成了新型系列离子液体催化剂，系统研究并获得了离子液体的酸碱性、氢键供体基团、吸供电基团、以及反应条件等对聚合反应催化性能、共聚反应产物结构选择性的影响规律；结合实验结果和量化计算，获得了聚合反应动力学，并揭示了离子液体氢键-静电协同催化促进聚合反应深度进行的催化机理；进一步研究了共聚产物热力学性能及应用前景。优化出并采用含有氢键供体基团的碱性功能化离子液体，实现了高效的酯交换-缩聚反应催化反应过程，聚碳酸酯聚合度可达到6万以上，且热力学性能良好，达国标水平。上述研究结果的取得为离子液体催化合成聚碳酸酯绿色新技术进一步放大以及后续推广提供了良好的理论和应用基础。本项目共发表高质量SCI论文8篇，申请中国发明专利2项，其中已授权1项，培养博士生和硕士生各2名。