Photoredox Polymerization of O-Carboxyanhydrides for Functionalized Polyesters

聚酯是重要的生物相容性聚合物，可在人体内降解。它们广泛用于日常应用，从服装和包装到农业和生物医药。然而，少量结构不同的聚酯限制了材料性能的范围和在需要机械强度的应用中的用途。为了应对这一挑战，弗吉尼亚理工学院和州立大学的Rong Tong教授的研究小组探索了新的合成策略，从天然氨基酸中生产具有更广泛化学结构和性能的聚酯。本研究开发了制备环境友好型和可生物降解聚酯的新反应，可作为商业应用中石油基塑料的替代品。多学科研究项目与本科生和代表性不足群体学生的教育和外展活动相结合。为弗吉尼亚州蒙哥马利县的初高中学生开发了一个推广项目，强调生物可降解聚酯的动手演示。在化学系大分子、超分子和纳米化学项目的支持下，汤教授的团队开发了新的可控聚合化学技术，以o -羧基水合物为原料合成功能化的可生物降解聚酯。o -羧基水合物是一类具有丰富侧链官能团的高活性单体。具体来说，本研究确定了光氧化还原催化系统，可以在室温下利用光有效合成功能化聚酯。这种聚合物不能用常规方法得到。采用新开发的催化剂，合成了与无规均聚物相比，具有更好的热性能和力学性能的立体规整聚酯。其他的研究活动包括光氧化还原开环聚合机理的研究和探索一锅，顺序控制，两个单体的光氧化还原共聚。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。

Polyesters are important biocompatible polymers that can degrade in human bodies. They are widely used in everyday applications ranging from clothing and packaging to agriculture and biomedicine. However, the small number of structurally-different polyesters limit the range of materials properties and utility in applications that demand mechanical strength. To address this challenge, the research group of Professor Rong Tong at the Virginia Polytechnic Institute and State University explores new synthetic strategies to produce polyesters from natural amino acids, that have a wider range of chemical structures and properties. This research develops new reactions for preparing environmentally-friendly and biodegradable polyesters that can serve as alternatives to petroleum-based plastics in commercial applications. The multidisciplinary research project is integrated with educational and outreach activities for undergraduates and students of underrepresented groups. An outreach program that emphasizes hands-on demonstrations of biodegradable polyesters is developed for middle and high school students in Montgomery County, Virginia.With the support from the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry, Professor Tong's group develops novel controlled polymerization chemistry to synthesize functionalized biodegradable polyesters from O-carboxyanhydries - an alternative class of highly active monomers with a rich variety of side-chain functionalities. Specifically, this research identifies photoredox catalytic systems that enable efficient synthesis of functionalized polyesters at room-temperature using light. Such polymers cannot be achieved using conventional methods. Using newly developed catalysts, stereoregular polyesters that possess improved thermal and mechanical properties compared with atactic homopolymers are synthesized. Additional research activities include the study of the photoredox ring-opening polymerization mechanisms and the exploration of one-pot, sequence-controlled, photoredox copolymerization of two monomers.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.