Valorization of pistachio shell filler: Optimization of filler content and injection molding parameters on physical and thermal characteristics of PLA based green composites

Growing concerns over resource depletion and rampant material pollution have sparked enormous interest in the use of natural, renewable fillers for the formulation of polymer composites. In this paper, Pistachio Shell Powder (PSP), an easily available agro-processing waste product, is comprehensively investigated as a biorenewable natural filler for the development of green and sustainable PLA biocomposites. Experimental design and analysis were performed using a statistical approach, Response Surface Methodology - Box-Behnken Design (RSM-BBD). This methodology was then applied for the optimization of the material properties by systematically altering the main input parameters, which are represented by the filler loading, melting temperature, pressure, and speed. The material characterization data obtained were optimized by using RSM for multifactor analysis, and the validity of the statistical design was carefully checked by the use of ANOVA. The key results obtained from this work clearly pinpoint PSP as a promising, high-potential, and eco-friendly reinforcement for biodegradable PLA biocomposites.