A Sustainable Bio-Filler for Epoxy Composites: Use of Pistachio Shell Powder

Abstract

The use of natural materials has become a crucial concern for humanity due to the limited quantity of petroleum-based products and their harmful impact on nature. The use of natural materials is inevitable for a greener and more sustainable world. Transforming agricultural industrial waste into a high-value product or a source of fuel can significantly benefit our country's economy and environment. Pistachio shell is one of the agro-industrial wastes and is abundant in our country. Our country can benefit economically and environmentally by utilizing and repurposing discarded shells, whether as fuel or as a valuable commodity. In this study, the shells of pistachios grown in Şanlıurfa were crushed in a stone mortar and reduced to certain sizes and turned into powder. Later, this powder was used as a bio-filler material for epoxy resin. Powders were used at 1% and 2% additive ratios and homogeneous mixing was carried out using both magnetic and ultrasonic mixers. The mechanical properties of the obtained biofilled epoxies were investigated and their microstructures were analyzed. Tensile test, bending test and hardness test were performed as mechanical tests and densities were measured. An improvement of 8% and 15% was detected in the maximum tensile and bending strength, respectively. The hardness and density values also increased by 8% and 1.7%, respectively. As a result of the microstructure analysis, no air bubbles were formed in the samples and no agglomeration occurred. Obtained results revealed that pistachio shell grown in Şanlıurfa can be used as bio-filler material.