Assessment of elaboration and performance of rice husk-based thermal insulation material for building applications

Abstract

Developing environmentally friendly building materials with low environmental impacts is receiving more attention nowadays to face the global challenges of climate change; building insulation materials made from agricultural waste can be used for their low environmental impact and to generate responsible supplies that utilize natural resources adequately. The study aims to assess a panel made from rice husk using the pulping method. An experimental design established the proportion of rice husk, the percentage of additive (NaOH concentration), boiling time and blending time. Taguchi’s method was applied to investigate the effect on density and thermal conductivity; the final panel with optimum conditions was morphologically analyzed using scanning electron microscopy (SEM); the thermal behavior was studied by thermogravimetric analysis (TGA); fire reaction and smoldering behavior were analyzed; and characterization in water absorption and acoustic absorption performances were established. The results show thermal conductivity values between 0.037 and 0.042 W/mK, a smoldering velocity of 3.40 mm/min, and a good acoustic absorption coefficient in octave frequency bands between 125 Hz and 4 kHz greater than 0.7. These characteristics are competitive with other insulating bio-based materials available on the market. This study employed chemicals utilized by other biomaterials for the pulping process and in flame retardants. However, it is important to investigate natural treatments or those with a diminished environmental impact.