Modular Molecular Editing of End-of-Life PBT for High-Performance Sustainable and 3D-Printable Platforms

Abstract

Engineering polyesters, particularly poly(butylene terephthalate) (PBT), are widely used but generate significant waste, with limited recycling options. Existing mechanical and chemical recycling strategies struggle to sustainably and efficiently reuse PBT, resulting in product performance degradation and making the recycling process more costly than the upstream synthesis routes for raw materials. Inspired by DNA editing technologies in molecular biology, a modular molecular editing strategy is proposed to sequentially modify the backbone and end groups of end-of-life PBT, transforming it into a high-performance, sustainable, and 3D-printable poly(butylene adipate-co-terephthalate) (PBAT) platform. Unlike traditional commercial PBATs that produce only single components, this platform surpasses them in tensile strength and toughness without requiring additional additives and features programmable properties for diverse applications, including injection-molded parts, 3D-printed components, films, packaging, fibers, and fabrics. The industrial scalability of this strategy is validated through successful 100-L pilot-scale production. The resulting PBAT allows closed-loop polymer-to-polymer recycling by reintroducing PBT or monomers, thereby enhancing its social sustainability. When recovery is no longer feasible, the materials remain ecologically sustainable through composting, avoiding harmful environmental accumulation. This work achieves a direct polymer-to-polymer conversion of end-of-life PBT into high-performance materials, with techno-economic analysis highlighting both environmental and economic advantages.