An in-depth analysis of the physico-mechanical properties imparted by agricultural fibers and food procebing residues in polypropylene biocomposites

Abstract

The use of agricultural and food procebing residues as potential reinforcements in plastics has been extensively studied. However, there is a large variation in the mechanical performance of agricultural fiber-based biocomposites due to different procebing materials and parameters. An in-depth comparison of the resulting effect of the agricultural filler on the matrix is often not pobible given the discrepancy in procebing conditions. This study seeks to determine the intrinsic properties of agricultural fibers and food procebing residues for their use in polypropylene biocomposites based on a standardization of experimental design. The effect of 25wt% loading of miscanthus, fall-And spring-harvest switchgrab, wheat straw, oat hull, soy hull, soy stalk, hemp and flax on the physico-mechanical properties of polypropylene biocomposites was investigated. The addition of fiber led to an improvement in flexural strength, flexural modulus, and tensile modulus, and a general decrease in tensile strength at yield, elongation at break and Izod impact strength. Scanning electron microscopy highlighted the interfacial adhesion, orientation and distribution of the fibers within the matrix, confirming that fiber length and dispersion within the matrix are positively correlated with mechanical properties. The crystallization of the polypropylene phase and a compositional analysis of the agricultural fibers and procebing residues were also compared to offer insight into the effect of the filler's intrinsic properties on the resulting material performance.