Methacrylated wood flour-reinforced "all-wood" derived resin for digital light processing (DLP) 3D printing

Additive manufacturing (AM) has led to the immense design freedom and fast production rates of wood-polymer composites (WPCs). However, vat photopolymerization-based AM techniques such as digital light processing (DLP) have yet to be exploited for the fabrication of complex and high resolution WPCs. This work demonstrates a microwave-assisted strategy for the rapid hydrophobization and functionalization of wood flour with meth-acrylate groups, in order to enhance its compatibility and interfacial interaction with novel wood-monomer derived photopolymer resins. The efficiency of this approach was exemplified in the inclusion of a high loading amount (10 wt%) of methacrylated wood flour to a biobased resin consisting of methacrylated eugenol and vanillin, without compromising the resin's dispersion stability and printability. Ultimately, the development of the resin culminated in the successful DLP 3D printing of wood flour-reinforced biobased composites that exhibited increases of 617%, 482%, and 31% in tensile strength, Young's modulus, and elongation at break, respectively, compared to resins without wood flour.