Research of Bioplastic Environmentally Safe Composites Based On Food and Agricultural Waste

Abstract

This article explores the development of sustainable bioplastic composites based on agricultural and food waste for agricultural applications, specifically as biodegradable seedling pots. This paper evaluates two bioplastic matrix types: one derived from banana peels and potato starch (BPS), and another from banana and potato peels (BP). The bioplastic composites were prepared in a two-stage process: initially, the bioplastic matrix was formed, followed by the incorporation of 25 wt% or 50 wt% crushed sunflower agro-waste. The sunflower agro-waste underwent fractional and microstructural analysis to determine the plant filler's structural and technological properties. Additionally, water absorption, impact strength, and flexural strength were evaluated for both the neat matrices and the resulting composites. Microstructural studies highlighted clear differences between the matrices. The peel-only matrix (banana and potato peels) featured a light brown surface with a sugary film but no significant caramelization. In contrast, the starch-based matrix (banana peel and potato starch) presented a dark surface, indicative of thermal caramelization. These findings indicate distinct processing behaviors and varying thermal stabilities during matrix formation. Optimal performance characteristics were achieved by the peel-only composite containing 25 wt% crushed sunflower agro-waste. The composite maintained mechanical integrity despite water absorption reaching 107% at 60 minutes and 122% at 24 hours. Additionally, it recorded the highest strength parameters among the studied formulations, featuring an impact strength of 3.1 kJ/cm² and a flexural strength of 43.5 MPa. These findings indicate an optimal balance among water retention, water resistance, mechanical strength, and formability for agricultural applications. The results confirm the viability of utilizing food and sunflower agro-waste to develop sustainable bioplastic composites. Specifically, the proposed materials are highly suitable for manufacturing biodegradable seedling pots that successfully combine operational strength and water-retaining capacity with subsequent biodegradation in soil.