Reactive mixing enables enzymatic depolymerization of recalcitrant or unsortable polyester wastes

• 成果类型: Article
• 署名作者: Garate, Hernan; Freymond, Clement; Breloy, Louise; Schindler, Michael; Pallis, Jack; Gibbs, Benjamin; Mansaku, Brian; Rondelez, Yannick; Creton, Costantino; Griffiths, Andrew D.; Leibler, Ludwik
• 署名单位: Universite PSL; Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI); Centre National de la Recherche Scientifique (CNRS); Sorbonne Universite; Universite PSL; Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI); Centre National de la Recherche Scientifique (CNRS); Universite PSL; Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI); Centre National de la Recherche Scientifique (CNRS)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9622
• DOI: 10.1073/pnas.2505611122
• 发表日期: 2025-07-22
• 关键词: crystallization behavior; poly(ethylene-terephthalate); copolyesters; degradation; kinetics; blends; state

摘要

Enzyme-catalyzed depolymerization allows efficient recycling of poly(ethylene terephthalate) (PET) bottles, which are easy to sort and made of slowly crystallizing PET. However, because crystalline phases are recalcitrant to enzymatic hydrolysis, this technology fails for rapidly crystallizing polyester wastes such as poly(butylene terephthalate) (PBT), unsortable mixed polyesters, or heterogeneous formulated PET waste streams. We show that melt transesterification and vitrimerization of mixtures of rapidly crystallizing polyester wastes, leveraging catalysts already present, produce copolyesters that crystallize slowly and are readily depolymerized. For example, reactive blending of a rapidly crystallizing postindustrial PET nonwoven waste with PBT improves depolymerization yields from 20% (PET nonwoven) and 1% (PBT) to 90%. Synergistic mixing can replace sorting, extending the scope of enzymatic recycling to recalcitrant, heterogeneous, and unsortable wastes. Significance Mixing rather than sorting can be the way to deal with recycling of plastic or textile waste streams. Enzymatic depolymerization produces building blocks of polymers that can be repolymerized to regenerate high-quality plastics. While this works for easily sortable and unformulated PET waste, like PET bottles, it fails for other PET waste streams and for other important polyesters like PBT. We find that synergistic melt mixing or vitrimerization in controlled proportions of heterogeneous and unsortable polyester wastes can produce, thanks to catalysts already present in wastes, copolymers, or networks that are readily depolymerized by available enzymes.