Development and Characterization of Peanut Shell Flour–Polypropylene Composite

Abstract

In this socioeconomic era, natural fillers are continuously being identified and investigated for the development of cost-effective, sustainable composites. Current work explores the potential of peanut shell flour (PNSF) as filler in polypropylene (PP) matrix. Five levels of filler loading of PNSF (10, 20, 30, 40 and 50) by weight percentage (wt%) are taken at two levels of maleic anhydride polypropylene (MAPP) coupling agent at 2% and 4% by weight. There is a decrease in the tensile, flexural and impact strength of the composites at all levels of filler loadings compared to unfilled and incompatible composites, while flexural modulus is increased by 243% at 50 wt% filler loading and 4 wt% MAPP. Storage modulus of the composite is increased by 35.2% compared to neat PP while reduced by 65% for incompatible composites. Overall, there is improvement in all the mechanical properties with incorporation of MAPP, and the best results are obtained at 4 wt% of MAPP. SEM shows good interphase between filler and matrix and relatively less voids with addition of coupling agent up to 30 wt% filler loading. Moisture absorption of the composites is restricted to 0.3% with addition of coupling agent even at maximum PNSF loading which indicates the utility of composites for outdoor applications.