Mechanical and Structural Properties of Biocomposites Reinforced with Bagasse Fibers from Sugarcane Overexpressing Sucrose Synthesis

In this study, the mechanical and structural properties of biocomposites fabricated using transgenic sugarcane bagasse overexpressing sucrose synthesis were investigated. The bagasse fibers were extracted from the transgenic and non-transgenic (NT) sugarcane stalk, then treated with alkalization and carbonization, and their chemical composition was analyzed. The treated fibers were reinforced to produce biocomposites, and their mechanical and structural properties were evaluated by measuring tensile strength, elongation at break, modulus of elasticity and scanning electron microscopy. The cellulose content ranged from 40.6–44.2% in transgenic sugarcane and was higher than in NT sugarcane, with the highest content observed in transgenic SPS3. However, the cellulose and hemicellulose contents were reduced, and the lignin content was significantly increased after carbonization treatment. Alkalization treatment significantly increased the tensile strength, with the highest value of 30.46 MPa obtained at 9% NaOH concentration in a biocomposite fabricated from transgenic SPS3 bagasse fibers. However, carbonization of the SPS3 bagasse fibers lowered tensile strength and slightly increased modulus of elasticity in the biocomposite. Morphological analyses showed roughened fiber surfaces after alkalization and the formation of voids in the carbonized composites. These results indicate the potential of the transgenic sugarcane bagasse fibers with high cellulose content as a renewable reinforcement material for biocomposites.