Effect of Fiber Chemical Treatments on Rice Straw Fiber Reinforced Composite Properties

Abstract

This work reports the effect of alkali, enzyme, and their sequential combination treatment on rice straw fiber properties (fiber diameter, aspect ratio, fiber length, bundle strength and elongation). The change in fiber properties and its association with rice straw fibers reinforced epoxy biocomposites has been studied. Biocomposites, prepared using the hand lay-up technique, were characterized using FTIR, TGA and SEM. The mechanical properties viz. tensile, flexural, impact and compression were measured according to the ASTM standards. Sound transmission loss and noise reduction coefficient of the composites was also determined. Results showed that the alkali and enzyme treatment to the rice straw significantly reduced fiber length and fiber diameter by 50%. Enzyme treatment caused the highest reduction in fiber diameter which increased the aspect ratio. The sequential combination of alkali and enzyme yielded significant improvements in the tensile (20%), flexural (22%), impact (98%), and compression (328%) strength of the composites. The noise reduction coefficient (0.95) of all rice straw composites was found excellent. Thus, alkali-enzyme pretreated rice straw fiber composite product is a good choice for agro-residue valorization and industrial product development.

Keywords

• rice straw fiber
• alkali-enzyme combination treatment
• agro-residue
• mechanical properties
• biocomposites
• sound transmission