Process design for performance improvement in purely ecofriendly composites for structural applications

ABSTRACT The chances of improving the properties of biocomposites lie in the efficient combination of processing and compositional parameters. Achieving required properties for a specified application will involve a systematic process design. In this study, we focus on achieving improvement in properties of the bio‐acrylic resin/wood fiber composites via a rational design of process and parameters. We aim to identify processing parameters where the wood fibers participate in the chemical reaction giving rise to a robust composite structure and consequently improved properties. First, processing variables were streamlined to arrive at an efficient, easy, and less expensive processing route. Thereafter, fiber treatment, length, aspect ratio, and weight fraction were correlated to optimize the structural properties. Composites were prepared with varying fiber weight fraction (35–60 wt %) and fiber aspect ratio (2–13.7) using raw wood fibers (RWFs) and raw cellulose fibers (RCFs) from commercial sources. Generally, it was noted that with appropriate choice of treatment and size of fillers, the curing reaction can be enhanced leading to improvement in properties. Results show that flexural strength increases with decrease in fiber aspect ratio for both treated and untreated fibers. Maximum tensile strength (96 MPa) was obtained with 45 wt % filler content and filler aspect ratio of 13.7 for untreated fibers. When compared at the same weight fraction and average fiber length, RCF composites possess about 40% improvement in flexural strength over that of RWFs. The best compromise between processing and properties of the finished ecocomposite varies with fiber aspect ratio, treatment, and weight fraction of the fillers. The study provides an insight for the development of high‐performance green composites for extended applications such as underbody panels, wheel wells, and underhood components. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48719.