Development of a pH-Responsive Mineral–Biopolymer Hybrid Bioplastic Derived from Eggshell Waste and Tamarind Seed Polysaccharides

Abstract

Globally, the amount of non-biodegradable plastic waste is increasing, posing a serious threat to the environment. Conventional plastics made from petroleum resources pollute soil and water habitats and linger in the environment for long periods of time. Biodegradable materials made from recyclable and waste-derived materials are becoming more popular as sustainable solutions to this problem. In this study, tamarind seed kernel was used as the main polymer source to create a biodegradable bioplastic. Natural polysaccharides found in tamarind seeds, a common agro-industrial by-product, can be used to make polymeric films. Citric acid was used as a crosslinking agent to increase structural stability, and glycerol was used as a plasticizer to increase the polymer matrix's flexibility.  To further strengthen the composite material, calcium carbonate made from eggshell waste was added as a reinforcing filler. Butterfly pea flower extract, which is abundant in natural anthocyanin pigments, was utilized to provide pH-responsive colour behaviour to further illustrate functional qualities. Solution casting was used to create the bioplastic film, which was then completely dried. The sustainable method for turning food and agricultural waste into biodegradable polymer materials that could be used in eco-friendly packaging and intelligent indication systems is demonstrated in this paper