Reprocessable and Repairable Bio‐Based Vitrimers From Acrylated Epoxidized Rapeseed Oil for Additive Manufacturing

ABSTRACT

Thermosets are difficult to reprocess and often rely on petroleum‐derived feedstocks, creating environmental and end‐of‐life challenges. This study addresses both issues by developing reprocessable bio‐based vitrimers tailored for additive manufacturing. Acrylated epoxidized rapeseed oil (AERO) was synthesized as a renewable UV curable precursor for constructing vitrimer networks capable of intrinsic and catalyst‐assisted transesterification. The influence of transesterification catalyst Zn(acac) ₂ , AERO content, and reprocessing cycles was systematically studied through real‐time curing behavior, stress relaxation, and thermo‐mechanical characterization. Catalyst‐free vitrimers exhibited notable stress relaxation of 34 min at elevated temperature due to the high density of β ‐hydroxyester groups, enabling intrinsic bond exchange. On the other hand, Zn(acac) ₂ ‐containing vitrimers demonstrated enhanced reprocessability with relaxation times as low as 10 min. Tensile strength recovery reached 98% after the first and 50% after the second reprocessing cycle. TGA‐FTIR analysis indicated increased CO ₂ and carbonyl‐rich volatile release in catalyst‐containing vitrimers, consistent with dynamic bond exchange reactions. Finally, the developed vitrimers exhibited excellent vat photopolymerization 3D printability and repairability, with repaired printed parts exceeding the original tensile properties by up to 2.9 times. These findings highlight the potential of vegetable oil‐based vitrimers as promising, customizable, repairable, and sustainable materials for next‐generation advanced additive manufacturing and circular polymer design.