离子液体中废旧聚碳酸酯的选择性氢解研究

The growing amount of waste polycarbonates (PCs) has become a severe problem to the environment due to their poor degradability. However, on the other side, waste PCs are potential chemical resources if they were reused properly. Therefore the effective recycling of waste PCs is an important topic both in scientific research and chemical industry. In this project, a new route for waste PCs recycling, the hydrogenolysis of PCs to corresponding monomers, was proposed. Ionic liquids (ILs) will be used as the reaction media due to their unique properties such as versatile designability and facile reusability. In order to tackle the difficulty in the hydrogenation of carbonate groups, a new activation mode called “dual activation” was proposed to practice the hydrogenation of carbonates under mild conditions. In this mode, functionial ILs and their derivatives will be used as “ionic promoters” to achieve the activation of carbonate groups, at the same time molecular H2 can be effectively activated by metal catalysts. The relation between catalytic performances and the properties of catalysts and ILs will be systematically investigated, and the synergistic effect of catalysts and ILs will also be discussed. Various methods such as experimental measurement, spectroscopic characterization and theoretical calculation will be employed to study the interaction between ILs and carbonates. The reasonable mechanisms for carbonates activation and hydrogenation reaction will be developed. This research will propose a new concept for cleaner recycling of waste PCs and lay the foundation for developing relevant techniques in chemical engineering science.

废旧聚碳酸酯量大，难以降解，对环境造成严重影响，但同时也是重要的潜在资源。如何实现废旧聚碳酸酯的有效回收利用是亟待解决的重要课题。本项目提出了对聚碳酸酯进行氢解，高选择性地制备相应聚合物单体这一全新的废旧聚碳酸酯回收利用的思路。基于离子液体可设计、易回收等独特性质，以离子液体作为反应介质进行聚碳酸酯的催化加氢反应。针对碳酸酯基团加氢条件苛刻的问题，将采用“双功能活化”的反应新模式，以功能化离子液体或其衍生物作为“离子型助剂”活化碳酸酯基团，金属催化剂活化氢气，实现较温和条件下聚碳酸酯的氢解生成单体。系统考察催化剂性质、离子液体性质等对加氢反应的影响规律与协同效应。将实验、表征与理论计算相结合，探究离子液体与聚碳酸酯的相互作用及碳酸酯基团的活化机制，获得多种清洁高效的催化剂-离子液体催化加氢体系和反应条件。本项目将为废旧聚碳酸酯的清洁利用提供全新的路线，为相关技术开发提供理论基础与科学依据。

聚碳酸酯是一种广泛应用的塑料产品。但由于其产量大、难降解，正对环境造成越来越严重的威胁。本研究从分子基础出发，研究离子液体与碳酸酯基团的相互作用。结合光谱手段，重点研究具有Lewis酸性和Lewis碱性的功能性离子液体在碳酸酯成键/断键中的催化作用，同时开发了新型的碳酸甘油酯合成催化剂，大大提高了反应活性与收率。并在本课题基础上，提出了新型多孔材料对于离子液体的有效负载方法，为固载离子液体以及基于固载离子液体的协同催化体系的工业化应用提供了新的思路。