CAS: Deconstructing Plastic and Agricultural Waste via Organosulfur Chemistry

在化学系大分子、超分子和纳米化学项目的支持下，克莱姆森大学的瑞德·史密斯教授将研究回收农业和塑料废物的方法，这两种未得到充分利用和对环境有害的废物是可持续经济的关键障碍。这项拟议的研究旨在通过以下方式造福社会：(1)阐明回收塑料垃圾的新的、可持续的方法；(2)使人们能够获得由植物衍生材料而不是石油制成的可持续产品；(3)减轻塑料垃圾对环境的破坏。这项工作还将通过可持续发展教育造福社会。关于绿色和可持续化学的资源将在网上提供，全世界都可以免费获取。该项目还将通过吸引来自历史上服务不足和代表性不足的群体的学生，帮助提高对科学、技术、工程和数学学位的参与度。这项工作旨在建立硫代裂解作为塑料和农业废物的化学循环/更新循环的机制。正在采用的硫代裂解方法包括将废物与元素硫反应生成有机物和有机硫化合物。这样衍生的混合物有望能够进行脱硫，以获得新的有机原料。这项研究的目的之一是建立硫与目标废物化合物(包括聚对苯二甲酸乙二醇酯、聚碳酸酯和木质素)中的官能团之间的反应途径。这些研究将涉及对真实废物和小分子模型化合物的反应的研究。预期的反应活性将促进C-S键的形成，因为硫将在350°C以下的温度下与有机物热分解过程中形成的自由基/自由基活性物种反应。这项工作旨在揭示C-S键形成的重要机理和微观结构，并合成新的有机硫聚合物。这项工作进一步寻求提供一锅协议，将塑料和生物质转化为新的聚合物和小分子衍生物，其能源成本显著低于许多当前化学循环战略所需的能源成本。这项研究有可能为社会做出贡献，使废旧水库能够被回收用于增值应用，这种回收方法利用S-S债券形成的热可逆性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Rhett Smith of Clemson University will research ways to recycle agricultural and plastic waste, two underutilized and environmentally detrimental waste streams that represent critical barriers to a sustainable economy. The proposed research aims to benefit society by (1) elucidating new, sustainable ways to recycle plastic waste, (2) allowing access to sustainable products made from plant-derived material instead of from petroleum, and (3) alleviating environmental damage of plastic waste in the environment. This work will also benefit society through sustainability education. Resources on green and sustainable chemistry will be made available online where they may be accessed for free worldwide. This project will also help to improve participation in science, technology, engineering and mathematics degrees by engaging students from historically underserved and underrepresented groups.This work seeks to establish thio-cracking as a mechanism for chemical recycling/upcycling of plastic and agricultural waste. The thio-cracking approach being pursued involves the reaction of waste materials with elemental sulfur to yield organics and organosulfur compounds. Mixtures so derived are expected to be amenable to desulfurization to give new organic feedstocks. One aim of the research is to establish reactivity pathways between sulfur and functionalities found in target waste compounds including polyethylene terephthalate, polycarbonates, and lignin. These studies will involve the study of reactions of authentic waste materials and of small molecular model compounds. The anticipated reactivity will facilitate the formation of C–S bonds as sulfur will react with radical/radical-reactive species formed in the course of the thermal decomposition of organics at temperatures below 350 °C. This work aims to unveil fundamentally important mechanisms and microstructures resulting from C–S bond-formation and yield new organosulfur polymers. This work further seeks to provide one-pot protocols to convert plastics and biomass into new polymers and small molecular derivatives at significantly lower energy cost than required for many current chemical recycling strategies. This research has the potential to contribute to society by enabling waste reservoirs to be reclaimed for value-added applications, with this approach to recycling drawing upon the thermal reversibility of S–S bond formation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.