Surface-methacrylated microcrystalline cellulose bioresins with soybean oil for additive manufacturing via vat photopolymerization

The additive manufacturing (AM) industry increasingly looks to differentiate itself by utilizing materials and processes that are green, clean, and sustainable. Biopolymers, bio-sourced raw materials and light weighting of parts 3D printed with photopolymer resins each represent critical directions for the future of AM. Here, we report a series of bio-based composite resins with soybean oil derivatives, up to 20% by weight of surface-methacrylated micro-crystalline cellulose (MCC) and 60% total bio-based content for vat photopolymerization based additive manufacturing. The ultimate tensile strengths of the materials were found to increase up to 3X, the Young's moduli increased up to 10X, and the glass transition temperature increased by 11.3 degrees C when compared to the neat resin without surface-methacrylated MCC as a filler. Working curves and shrinkage factors were used to demonstrate how the surface-methacrylated MCC causes changes in the dimensions of printed parts, to facilitate development of optimized print parameters based on the UV intensity of the 3D printer being used. These results will allow further development of commercial 3D printable resins with a high concentration of bio-based fillers that print well and perform on par with conventional resins.