Search for a ‘Green’ Composite Material: An Attempt to Fabricate Cellulose Nano-Fiber Composites using Liquid Composite Molding

Abstract

Plant-derived cellulose nano-fibers (CNF) have remarkable mechanical properties at the nano scale. Owing to the bio-based and biodegradable properties of CNF, its nanocomposite with a bio-based resin has the potential of becoming an attractive ‘green’ material for use in the automotive, aerospace, and other engineering applications. However, the efforts to produce scalable nano-composites from CNF are not yet near fruition. In this short study, scalable CNF composites were made using a bio-based resin through an improvised version of the liquid composite molding (LCM) process. Of the two different types of CNF preforms created (one isotropic and the other anisotropic) using the freeze-drying process, the former was considered for making the CNF composite. Inferiority of the CNF composite vis-à-vis a glass-fiber composite in tension tests revealed that the CNF did not interact with the resin as fully dispersed nanoparticles, but rather as the microscopic skeleton of CNF preforms. Two different porous, isotropic CNF preforms (of silane and non-silane treated types) were made using the freeze-drying process. The SEM micrographs and tension tests revealed that the silane-treated preforms produced better composites with higher strength and stiffness, and with better interfacial adhesion and less voids. The developed LCM technique presents a plausible method of scaling-up the production of CNF nanosomposites.