Recycling Post-Consumer Polyesters Bottles and Fabrics to Photocurable Covalent Adaptable networks

Abstract

Recycling aromatic polyester waste into UV curable covalent adaptable networks (CANs) offers a promising pathway toward more circular materials. Here, we present a straightforward strategy to convert post consumer polyethylene terephthalate (PET) bottles and polybutylene terephthalate (PBT) fabrics into photocurable, mechanically reprocessable, and chemically degradable CANs. PET and PBT were first depolymerized via glycolysis or alcoholysis to yield BHET and BHBT, which were subsequently methacrylated to form resins PR and FR. A third resin, SBJR, containing dynamic imine (Schiff base) linkages, was synthesized from methacrylated vanillin and Jeffamine to introduce reversible bonding into the network. These components enabled fabrication of two permanently crosslinked polymers (PR100, FR100) and two covalent adaptable networks (CAN1, CAN2). Structural analysis verified the expected chemical transformations, and all materials exhibited good thermal stability, with CANs showing slightly reduced T5% due to flexible aliphatic segments and reversible imine bonds. Rheological creep and stress relaxation studies supported associative imine exchange as the governing mechanism without network dissociation. CAN2 also demonstrated robust solvent resistance and could be mechanically recycled and chemically degraded through imine exchange driven depolymerization. Overall, this work establishes an efficient molecular design framework for transforming plastic and textile waste into photocurable materials, advancing value of plastic waste as a resource for new materials and reduced environmental pollution.