effect of modified waste bio-filler for sustainable reinforced polymer composite for a circular economy

Circular economy aims to create a more sustainable and resilient economic system by closing the loop on material flows, reducing environmental impact, and leading to a restorative and regenerative approach to production and consumption. the study focuses on repurposing recycled expanded polystyrene (r-eps), commonly found as disposable utensils, and incorporating spent tea leaves powder (stlp), a globally popular beverage byproduct. the study seeks to enhance bio-composite properties through stlp integration with surface treatment and modifications. the materials to be used, r-eps and stlp, are collected through waste management and pre-treated with organic surfactants before being dried in an oven at elevated temperatures to remove any moisture present. stlp is subsequently dispersed within the r-eps polymer matrix in the two-roll mill, followed by crushing and compression molding to produce astm standard samples. the samples of untreated and treated r-eps/stlp are tested for both mechanical and thermal properties. the results indicate improvements in various properties. tensile strength, modulus, flexural strength, and impact strength increased by 30%, 40%, 17%, and 23% respectively. elongation and hardness experienced a decrease of 33.3%, and 9.9%. the optimal enhancement is observed with the addition of 3 wt. % of the treated stlp into the polymer matrix. moreover, thermogravimetric analysis shows an increase in thermal stability with reinforcements significant rise of 10°c. the water absorption test revealed no significant water absorbance capability in the composite, whether incorporating untreated or treated stlp in r-eps. fourier transform infrared (ft-ir) spectroscopy is used to analyze the morphological characteristics and chemical bonding in treated r-eps/stlp. the results reveal that the chemically treated stlp exhibits compatibility with the r-eps and can be used to fabricate a bio-composite polymer for various industrial packaging applications. therefore, this research highlights the broader implications by demonstrating the potential of repurposing waste materials into value-added products with enhanced properties.