From Glassy Plastic to Ductile Elastomer: Vegetable Oil-Based UV-Curable Vitrimers and Their Potential Use in 3D Printing

Current UV-curable resins based on acrylate or methacrylate monomers are mostly derived from nonrenewable petroleum feedstocks, and the cured resins are not easily repairable or reprocessable due to the stable cross-linked network. In this work, bio-based UV-curable dimethacrylate compounds are synthesized via reaction of the vegetable oil-derived dimer acid with glycidyl methacrylate. The length and flexibility of the chain segment between the two methacrylate groups are manipulated to tune the properties of the cross-linked polymer materials. The UV-cured materials exhibit a tensile strength of up to 9.2 MPa and an elongation at break of up to 66.4%. At elevated temperatures (>160 °C), the thermally induced dynamic transesterification reaction (DTER) between hydroxyl groups and ester bonds in the network structure provides repairability to the material. Use of the UV resin for three-dimensional (3D) printing is demonstrated. The printed objects exhibit unique welding and shape-changing properties owing to the thermally induced DTER. This work integrates the concepts of UV curing, vitrimer preparation, 3D printing, and bio-based polymers, demonstrating a feasible approach for the sustainable design of polymer materials.