A Comparative Study on the Mechanical and Biodegradation Characteristics of Starch-Based Composites Reinforced with Different Lignocellulosic Fibers

Eco-friendly green composites made of bio-based polymers and reinforced with natural fibers have been introduced as a sustainable alternative to the non-renewable petroleum-based materials. The aim of this work is to assess the variations in the mechanical and biodegradation behavior of starch-based composites after being reinforced with different lignocellulosic fibers (i.e., flax, date palm, banana, and bagasse). The investigated composites, of 50 wt% fiber content, were prepared using compression molding. The biodegradation behavior was evaluated using soil-burial composting, while the mechanical investigation was conducted during and after the biodegradation test. Flax composites showed the highest tensile strength and modulus of elasticity, while banana composite had the lowest tensile strength. Both Kelly-Tyson model and Halpin-Tsai mathematical models underestimated the prepared composites' tensile strength and modulus of elasticity, respectively, except for the case of flax fibers' composites. The tensile strength and modulus of elasticity for all composites decreased dramatically during the first week (more than 50% reduction), then further gradual deterioration took place until the end of composting. The weight loss of the composites was gradual during the burial period. By the end of the test (6 weeks), the residual weights were 59, 47, 46, and 35% for flax, palm, banana, and bagasse composites, respectively.