Studies on the Mechanical Properties of Biodegradable Unripe Banana Starch Composites Reinforced with Natural Pineapple Leaf Fibres (Annas comosus L. Merr.)

The development of biodegradable composites has gained significant attention due to the environmental concerns associated with synthetic polymers. Unripe banana starch, characterized by its high amylose content, presents excellent film-forming properties and biodegradability, making it a promising matrix for composite fabrication. Despite these advantages, its poor mechanical properties restrict its standalone use in structural applications. To improve its performance, reinforcement with natural fibres such as pineapple leaf fibres has been explored. Pineapple leaf fibres, obtained as agricultural waste, exhibit remarkable tensile strength, flexibility, and low density making them an 
ideal reinforcement material for starch-based composites. This study focuses on the mechanical characterization of a biodegradable composite derived from unripe banana starch (Musa sapientum L.) and short pineapple leaf fibres (Ananas comosus L. Merr.). The composite was fabricated with varying fibre content (0–5 g), and its mechanical properties were evaluated through tensile strength, flexural strength, compression strength, elongation at break, impact resistance, and hardness testing. Results indicated that fibre reinforcement significantly enhanced the mechanical properties of the starch based composite. The highest tensile strength and elongation at break were recorded in the sample containing 5g of fibre, demonstrating improved ductility and load-bearing capacity. Compression and flexural tests revealed a progressive increase in mechanical resistance with fibre addition, confirming effective stress distribution within the matrix. 
Impact and hardness tests further corroborated these findings, with a noticeable improvement in impact resistance and structural integrity. These findings suggest that the incorporation of pineapple leaf fibres into banana starch composites significantly OKUNZUWA and UWUIGBE/BJPS, 2(1), June, pg. 193-212 (2025) 194 improves mechanical properties, making it a viable alternative to conventional plastics in 
sustainable applications.