Additive Manufacturing of Wood-Based Polymer Composites Fabricated Using Vat Photopolymerization for Design Applications

In the present research work, wood-based composites were prepared by adding different poplar powders within a soybean-oil-based resin choosing liquid crystal display (LCD) as vat photopolymerization (VP) among the additive manufacturing (AM) technologies useful for polymer processing. The aim was to combine the advantages of AM with the valorisation of poplar wood powder wastes from the plywood industry to obtain innovative and more sustainable composite materials as alternatives to the classical fossil-based materials, for interior design applications. Several photocurable formulations were prepared using an acrylate epoxidized soybean oil (AESO) resin as polymer matrix and isobornyl methacrylate (IBOMA) as reactive diluent, in the presence of 2 wt.% of phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide (BAPO) as photoinitiator. Bio-based composites were obtained by adding to the AESO formulations 3 wt.% of different wood poplar powders (PI and PIV), two by-products coming from plywood panel production, and by 3D printing different parts in an LCD 3D printer. A comprehensive characterization of the composites fabricated via VP was carried out. Rheological, thermal, morphological, and mechanical measurements were done to investigate the final properties of the 3D printed wood-based composites. Several 3D printed components were fabricated showing different level of detail and complexity. The specimens showed enhanced final properties, in terms of elastic modulus, glass transition temperature, and storage modulus, due to the reinforcing effect induced t the presence of the fillers. This research demonstrates that bio-based components can be successfully 3D printed via LCD, including objects with potential application in interior design, such as joints and connections, highlighting the material’s suitability to realize customized and more sustainable elements for design-oriented applications.