New Directions for the Synthesis and Degradation of Renewable and Recyclable Plastics Using Homogeneous Catalytic (De)hydrogenation

我们日常使用的许多物品都是由塑料制成的。特别是，某些类型的塑料，如聚氨酯、聚氨酯和聚碳酸酯，在建筑材料和生物医学工业中有着重要的应用，全球市场价值为860亿英镑/年。然而，它们的工业生产涉及有毒和危险的原料，如二异氰酸酯和光气。因此，开发更环保的方法，避免这些致命的起始材料来生产有用的塑料是当前社会的迫切需要。提议的奖学金旨在开发一种新的绿色和可持续的方法，通过二醇和二胺与甲醇脱氢偶联的过程来合成这种塑料。拟议的方法将用甲醇取代致命试剂（如二异氰酸酯和光气）的使用，甲醇不仅比目前使用的试剂毒性更小、更便宜，而且是可再生的，可以从生物质或二氧化碳中生产。与相应领域的专家合作，还将研究合成聚合物在环境研究、药物输送和医学成像等多个领域的潜在应用。本提案中概述的研究的成功将有利于环境、经济和人类安全。另一个相关而严重的问题是塑料污染。事实上，超过100万只鸟类和超过10万只海洋哺乳动物死于食用或被塑料垃圾缠住。除了对野生动物有害外，塑料垃圾也是一种未开发的资源，因为现有的用途很少，效率也很低。拟议的计划将通过开发利用催化氢化方法对聚氨酯、聚氨酯和聚碳酸酯类塑料废物进行化学回收的新途径，释放塑料废物的经济潜力。总体而言，通过催化脱氢（用于合成塑料）和氢化（用于降解塑料废物）的组合方法，该计划设想建立塑料的闭环生产，以实现循环经济，在满足人类经济需求的同时减少对生物圈的危害。

Many of the items we use on a daily basis are made of plastics. In particular, certain types of plastics such as polyureas, polyurethanes, and polycarbonates have significant applications in construction materials and the biomedical industry and have a global market value of £86 billion/year. However, their industrial production involves toxic and hazardous starting materials such as diisocyanates and phosgene gas. Thus, the development of greener methods that avoid such fatal starting materials to produce useful plastic is a pressing need of current society. The proposed fellowship aims to develop a new green and sustainable approach for the synthesis of such plastics by the process of dehydrogenative coupling of diols/diamines with methanol. The proposed methodology will substitute the use of deadly reagents (such as diisocyanates, and phosgene gas) with methanol which is not just less toxic and cheaper than the currently used reagents but is also renewable and can be produced from biomass or CO2. The potential applications of the synthesized polymers in multiple areas such as environmental studies, drug delivery, and medical imaging will also be studied in collaboration with experts in the corresponding areas. The success of the research outlined in this proposal will benefit the environment, the economy, and human safety.Another related and serious problem is that of plastic pollution. In fact, more than 1 million birds and over 100,000 sea mammals die from eating or getting tangled in plastic waste. Aside from harming wildlife, plastic waste is an untapped resource, because existing uses for it are few and inefficient. The proposed program will unlock the economic potential of plastic waste by developing a new route for chemical recycling of plastic wastes of type polyureas, polyurethanes, and polycarbonates using the approach of catalytic hydrogenation. Overall, using a combined approach of catalytic dehydrogenation (for the synthesis of plastic) and hydrogenation (for degradation of plastic waste) this program envisions establishing the closed-loop production of plastics to enable a circular economy, which addresses the economic needs of humanity while reducing harm on the biosphere.