Renewable methacrylate resin for vat photopolymerization derived from post‐consumer polyester waste

This study addresses the growing need for sustainable materials in vat photopolymerization (VP), a widely used additive manufacturing technique. Conventional VP resins rely heavily on fossil‐based feedstocks, which poses environmental challenges. To mitigate this, we valorized end‐of‐life poly(ethylene terephthalate) into renewable methacrylate resins suitable for 3D printing. Post‐consumer polyester waste was depolymerized into bis(2‐hydroxyethyl) terephthalate (BHET), which was subsequently functionalized via microwave‐assisted methacrylation using methacrylic anhydride. Compared with conventional heating, this approach significantly reduced the reaction time, which aligns with green chemistry principles. The resulting methacrylated BHET crosslinker was incorporated into photocurable resin formulations. Resin viscosities fell within the VP processing window, enabling successful stereolithographic 3D printing of complex geometries with high precision. Mechanical and thermal characterization revealed tunable properties; increasing crosslinker concentration enhanced glass transition temperature, crosslink density and Young's modulus. This work demonstrates the feasibility of converting technosphere feedstock into 3D printable photopolymers, reducing the reliance on petroleum‐based resins and supporting circular economy principles.