Valorization of Poplar Wood Wastes Into <scp>3D</scp> ‐Printed Soya Oil‐Based Composites by Vat Photopolymerization for Interior Design

ABSTRACT The research aims to develop innovative bio‐based polymer composites through vat photopolymerization (VPP) 3D printing (3DP) and to test their use in creating a joint for furniture design, thereby constituting a proof of concept for the project “Made in Italy Circolare e Sostenibile‐MICS.” Formulation composed of 50 wt% acrylate epoxidized soybean oil (AESO) resin and 50 wt% isobornyl methacrylate (IBOMA) as a reactive diluent is prepared with 2 phr phenylbis(2,4,6‐trimethylbenzoyl) phosphine oxide (BAPO) as a radical photoinitiator. The photopolymerization is conducted using liquid crystal display (LCD) 3DP technology. Two different poplar wood powders (namely, P I and P IV ), obtained from waste materials of the plywood manufacturing process, are incorporated into the resin at concentrations of 3 phr to produce the final bio‐based composites. Sedimentation and rheological tests are carried out on the photocurable resins to assess their viscosity and 3D printability. Once the optimal printing parameters are established, specimens for mechanical characterization and different structures, gradually evolving into more intricate designs, are 3D‐printed. The results show that the bio‐composites represent a promising alternative for producing joints, connections, nuts, and screws for various design applications, exhibiting high dimensional accuracy, high resolution, and well‐defined geometries.