EFRI E3P: Reincarnation of Polymers for the Circular Economy

美国的塑料垃圾回收率不到10%。低回收率造成的问题包括：1）废塑料泄漏到自然环境中，并伴随着破碎成微塑料颗粒污染，对生态系统和人类健康产生负面影响，2）我们的石油和天然气供应枯竭-需要使用大量能源来制造新塑料，以及3）与使用回收材料相比，温室气体排放增加。微塑料污染问题特别令人担忧，因为这些小塑料颗粒正在进入人类食物链，而微塑料消费这些非常小的塑料颗粒的影响目前尚不清楚。此外，一些分析表明，加强回收将导致就业机会的急剧增长;可以创造超过100万个就业机会。在这个新兴前沿研究和创新项目中，一个跨学科和多元化的团队将致力于改变塑料行业，以消除报废废物。对废塑料进行分类、清洁和转化的革命性方法能够实现转型成果;随着更多的塑料被重复使用而不是被扔进垃圾场，目前的“生命终结”思维变成了整体的“周期终结”思维。通过这项研究开发的知识和技术将提高塑料回收率，更多的回收创造就业机会，同时有助于保护环境和人类健康。投资改进回收技术将有助于美国在不断变化的全球经济中保持竞争力。参与计划活动是包容性的，并通过与社区可持续发展计划的新颖的跨学科互动，并通过为K-12和本科生提供外展计划来促进。一个多元化团队将与密歇根州的部落学院合作，这是少数民族服务机构，以支持美国土著社区有意义地参与STEM研究。通过将传统知识融入到项目教学中，将培养对可持续性问题的深刻和文化多样性的认识。该项目的目标是开发和展示回收塑料的新方法。该项目的范围包括新的方法，以脱脂聚合物和再生的产品成为有价值的材料。受控实验辅之以化学动力学模型、分子尺度模拟和机器学习是所使用的主要方法。将利用生命周期分析方面的专门知识来评估和确定新的创新办法的效用。通过化学和生物化学催化转化的级联实现通过解聚的化学再循环。与化学科学中迅速出现的创新趋势相一致，化学和酶催化转化的协同组合将通过化学氧化的案例研究来证明，然后通过酶催化脱羧来创建石脑油（混合烷烃）。由此产生的低温级联方法将与目前最先进的热解技术进行比较; LCA将指导工艺改进，并用于评估这种新的级联方法是否提供了改进的可持续性指标。高温热解过程与低温级联途径的直接比较可以大大提高塑料回收领域的知识;迄今为止，还没有这样的全面评估。然而，关于这两条途径中哪一条值得今后重视的问题影响深远。联合反应器分离器的创新使用将被证明，预计将是一个上级的方法来生产单体从废塑料。再聚合将作为一种手段来追求“再生”报废塑料到全新的，高价值的，特殊的聚合物在他们的下一个生活中使用。废聚乙烯的氧化将用于生产二羧酸，而对废聚对苯二甲酸乙二醇酯的氨解的创新使用将提供芳族二胺。将所得单体掺入新形成的聚合物中，包括聚酯、聚酰胺、聚芳酰胺、聚酯酰胺和聚酯芳酰胺。这些聚合物比回收的废塑料昂贵得多（2- 3倍），提供了一种经济激励，可以有效地提高回收率。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The United States recycles less than 10% of generated plastic waste. Low recycling rates create problems including: 1) leakage of waste plastic into the natural environment and accompanying fragmentation into microplastic particulate pollution that negatively affects ecosystems and human health, 2) depletion of our oil and natural gas supplies - the need to use lots of energy to make new plastics, and 3) increased greenhouse gas emissions compared to using recycled materials. The microplastics pollution problem is particularly concerning because these small plastic particles are entering the human food chain, and the effects of microplastic consumption of these very small plastic particles is currently unknown. Furthermore, several analyses have shown enhanced recycling will lead to dramatic job growth; upwards of a million jobs could be created. In this Emerging Frontiers in Research and Innovation project an interdisciplinary and diverse team will work to transform the plastics industries to eliminate end-of-life waste. Revolutionary approaches to sorting, cleaning, and transforming waste plastics enables a transformational outcome; present “end of life” thinking becomes holistic “end of cycle” thinking as more plastics are repeatedly used rather than thrown into a dump. The knowledge and technologies developed through this research will enable greater rates of plastics recycling, more recycling creates jobs while helping to protect the environment and human health. Investing in improved recycling technologies will help the USA remain competitive in the ever-changing global economy. Participation in programmatic activities is inclusive and fostered by novel cross-disciplinary interaction with Community Sustainability programs and through delivery of outreach programs for K-12 and undergraduate college students. A Diversity Team will work in partnership with the tribal colleges of Michigan, which are Minority-serving institutions, to support meaningful participation in STEM research by the Native American community. A deep and culturally diverse awareness of sustainability issues will be fostered through incorporation of traditional learnings into program pedagogy.The goal of the project is to develop and demonstrate new approaches to recycling plastics. The scope of the project includes novel ways to depolymerize polymers and repolymerize the products into valuable materials. Controlled experimentation complemented by chemical kinetic models, molecular-scale simulations, and machine learning are the primary methods used. Specialized expertise in life cycle analysis (LCA) will be used to assess and establish the utility of the new and innovative approaches. Chemical recycling through depolymerization is accomplished through cascading of chemically and biochemically catalyzed transformations. Consistent with a rapidly emerging innovation trend in the chemical sciences, synergistic combinations of chemically and enzymatically catalyzed transformations will be demonstrated through the case study of chemical oxidation followed by enzymatically catalyzed decarboxylation to create naptha (mixed alkanes). The resulting low-temperature cascaded approach will be compared to the present state-of-the-art of thermal pyrolysis; LCA will guide process improvements and be used to assess if this new cascading approach provides improved sustainability metrics. A direct comparison of a high-temperature pyrolysis process with a low-temperature cascading pathway can substantially advance knowledge in the plastic recycling field; to date, no such comprehensive evaluation is available. However, the implications regarding which of the two pathways deserves future emphasis are profound. The innovative use of combined reactor-separators will be demonstrated and is expected to be a superior approach to producing monomers from waste plastics. Repolymerization will be pursued as a means of “reincarnating” end-of-life plastic into brand new, high-value, specialty polymers for use in their next life. Oxidation of waste polyethylene will be used to produce dicarboxylic acids, and the innovative use of ammonolysis on waste polyethylene terephthalate will provide aromatic diamines. Resulting monomers are to be incorporated into newly formed polymers including polyesters, polyamides, polyaramids, polyesteramides, and polyesteraramids. These resulting polymers are considerably more expensive (2-3x) than the reclaimed waste plastic, providing an economic incentive that can effectively increase recycling rates.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.