Thermal, mechanical, and sound absorption properties of sugarcane bagasse–rice husk hybrid polymer composites

Abstract

Natural fiber reinforced composites are explored more and more as sustainable alternatives to synthetic materials, but the challenge of obtaining a balance between thermal insulation, mechanical strength and acoustic absorption is still an important problem. This study evaluates the performance of hybrid composites with sugarcane bagasse (SCB) and rice husk (RH) in weight ratios of 100%, 70/30, 50/50 and 30/70 using thermoset resin matrix. Thermal conductivity was measured by Lee's Disc Method, the 100% RH sample obtained the lowest thermal conductivity of 0.03502 W/mK, which showed a good insulation performance. Mechanical characterization according to the standards of tensile strength and flexural strength of the samples in accordance with ASTM D3039, D790, and D256 showed that the 50/50 SCB-RH composite had the highest tensile strength (80.1 MPa) and flexural strength (78.9 MPa). Acoustic performance, which was determined through ASTM E1050-12, and the 50/50 hybrid was determined as the most effective sound absorber with a peak coefficient of 0.75 at 1900 Hz. The SEM analysis revealed that there was good dispersion of fibers and low voids in hybrid samples and this is one of the reasons why they exhibit better multifunctional behavior. In general, the 50/50 SCB-RH composite has the best thermal, mechanical and acoustic performance and it has great potential in the application of insulation and noise control in the automotive and architectural industry.