SusChEM: Polyesters from Sustainable C1 Feedstocks

在这个由化学部高分子、超分子和纳米化学计划资助的项目中，佛罗里达大学的Stephen A.Miller将合成并表征一类新的生物可再生聚酯，目标是热塑性包装应用。这种理想的聚合物类似于脂肪族聚酯聚乙醇酸(PGA)，被称为PGAβ。然而，该方法避免了目前合成PGA所需的多步生产乙醇酸，也避免了生产聚乳酸所依赖的发酵技术。甲醛和一氧化碳的阳离子交替共聚很容易适应共聚单体的加入，从而允许轻松地调节热机械性能。典型的共聚单体是廉价的环氧化物，它会破坏聚合物主链的结构规律性，从而降低结晶度、模数和脆性。结构-性能分析将为模拟化石燃料塑料的性能提供指导和预测最佳共聚目标。此外，还将调查过渡金属催化剂调节反应条件的能力，并将进行一系列聚合物降解实验，以评估将PGA Beta安全返回环境所需的时间和条件。传统的商品塑料是通过成熟的路线制造的，并具有经过证明的材料特性。然而，绝大多数来自有限的资源，如石油和天然气，由于降解行为缓慢，对废物的积累有很大贡献。这项研究解决了在开发一种新的、可持续的塑料类别方面的这些缺陷。高效设计的合成依赖于可以从生物质中获得的原料，如森林副产品和不可食用的农业废物。塑料的性能可以进行微调，以模仿和取代现有的化石燃料塑料。这些塑料不会堆积在垃圾处理场和环境中，而是会友好地降解回环境友好的化学成分。

In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, Stephen A. Miller of the University of Florida will synthesize and characterize a new class of biorenewable polyesters, targeting thermoplastic packaging applications. The desired polymers resemble the aliphatic polyester polyglycolic acid (PGA) and are termed PGA beta. However, the proposed approach avoids the multistep production of glycolic acid currently necessary for PGA synthesis and it avoids fermentation technology upon which polylactic acid (PLA) production depends. The cationic alternating copolymerization of formaldehyde and carbon monoxide is readily adapted to the incorporation of comonomers, allowing for the facile modulation of the thermomechanical properties. Typical comonomers are inexpensive epoxides, which serve to disrupt the structural regularity of the polymeric main-chain, and thus will decrease crystallinity, modulus, and brittleness. Structure-property analyses will provide guidance and predict the best comonomer targets for mimicking the properties of fossil fuel-based plastics. Also, transition metal catalysts will be surveyed for their capacity to moderate the reaction conditions, and a battery of polymer degradation experiments will be conducted to assess the timescale and conditions for safely returning the PGA beta back into the environment.Traditional commodity plastics are made via well-established routes and have proven material properties. However, the vast majority derives from finite resources, such as petroleum and natural gas, and contributes greatly to the accumulation of waste because of slow degradation behavior. This research addresses these drawbacks in developing a new, sustainable class of plastics. The efficiently designed synthesis relies on feedstocks that can be sourced from biomass, such as forest byproducts and inedible agricultural waste. The properties of the plastics can be finely tuned in order to mimic and replace existing fossil fuel-based plastics. Instead of accumulating in waste disposal sites and in the environment, these plastics will degrade benignly back into the environmentally friendly chemical components.