Development and Characterization of Novel Cellulose-Based Soy Biopolymer for Sustainable 3D Printing

Abstract

Most materials currently used in 3D printing are non-renewable petroleum thermoplastics, which will not support the anticipated growth of 3D printing as the applications and demand of the industry continue to rapidly evolve. In this study, a cellulose-based soy biopolymer (CSBP) feedstock for 3D printing applications is developed. With cellulose-based products accounting for one third of Canada’s municipal solid waste, this provides both a solution to the growing problem of environmental pollution and global warming, as well as the need for sustainable materials in 3D printing. A formulation of soy protein isolate, cellulose and additives has been developed to produce a print media to be used for extrusion 3D printing. A soy-protein component mixed with formulation additives allows for the creation of a self-curing binder, in combination with cellulose as a filler to improve the resulting mechanical properties. A synergistic combination of protein crosslinking, film formation and solvent evaporation is employed to create solid objects with CSBP. Most importantly, this formulation is composed entirely of generally regarded as safe (GRAS) formulation components to become an alternative for extrusion 3D printing that is biodegradable, non-toxic and has environmentally friendly synthesis. The material developed is paste-like in its uncured state and requires a syringe extrusion mechanism for applications in 3D printing. With CSBP established as a 3D printable material through a syringe-based mechanism, multiple physical characterizations are performed to characterize CSBP and provide insights on its overall properties. Furthermore, investigation of some preliminary end-user applications of CSBP were performed to provide insight into the future use of this new biomaterial. Collectively, this study developed and characterized the use of CSBP feedstock for 3D printing, capable of recycling paper into a new biomaterial. CSBP exhibited a variety of tunable properties as a function of the curing conditions and time and was found to be naturally biodegradable and biocompatible. Preliminary applications in the adhesive and packaging industries as well as the creation of drug delivery systems were achieved with encouraging initial results. This work highlights a solution to global issues in both the recycling of paper waste and provide a sustainable pathway for the ever-expanding applications of 3D printing.