Zhang Shun, Xu Wenhao, Zhao Xuan, Liu Yifan, Yan Lei, Liu Xuehui, Xu Shimei, Wang Yu-Zhong
Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu, 610064, China.
Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Architecture and Environment, Sichuan University, Chengdu, 610064, China.
Angew Chem Int Ed Engl. 2025 Aug 4;64(32):e202505490. doi: 10.1002/anie.202505490. Epub 2025 Jun 12.
Waste plastics represent a new resource for the chemical industry. In this study, we demonstrate a solvent-switching strategy to upcycle waste polyethylene terephthalate (PET) into monomer terephthalic acid (TPA) and key bulk feedstocks for biodegradable polymers, such as lactic acid (LA) or glycolic acid (GA). PET undergoes rapid and mild depolymerization into its monomers TPA and ethylene glycol (EG) under the catalysis of a manganese complex. When methanol (MeOH) is used as the solvent, it undergoes selective dehydrogenative coupling with in situ generated EG, efficiently yielding TPA and LA with yields exceeding 98%. By replacing MeOH with tert-amyl alcohol (t-AmOH), PET is quantitatively converted into TPA and GA. The PET conversion mechanism was elucidated through deuterium-labeling experiments and molecular model studies. This work presents a sustainable and innovative approach for upcycling waste PET into high-value products while opening a new route to synthesize biopolymer monomers, which are essential for developing chemically recyclable and biodegradable polymers, thereby advancing the production of sustainable single-use polymer products.
废塑料是化学工业的一种新资源。在本研究中，我们展示了一种溶剂转换策略，可将废弃聚对苯二甲酸乙二酯（PET）升级循环为单体对苯二甲酸（TPA）以及用于生物可降解聚合物的关键大宗原料，如乳酸（LA）或乙醇酸（GA）。在锰配合物的催化下，PET能快速且温和地解聚为其单体TPA和乙二醇（EG）。当使用甲醇（MeOH）作为溶剂时，它会与原位生成的EG发生选择性脱氢偶联反应，高效生成TPA和LA，产率超过98%。通过用叔戊醇（t-AmOH）替代MeOH，PET可定量转化为TPA和GA。通过氘标记实验和分子模型研究阐明了PET的转化机理。这项工作提出了一种将废PET升级循环为高价值产品的可持续创新方法，同时开辟了一条合成生物聚合物单体的新途径，这些单体对于开发可化学回收和生物可降解的聚合物至关重要，从而推动了可持续一次性聚合物产品的生产。
