Chemical-free thermal-acoustic panels from agricultural waste for sustainable building materials

To address the pressing need for sustainable building materials, this study introduced an innovative and ecofriendly approach to manufacturing thermal-acoustic panels, utilizing agricultural waste with rice straw as the primary material. Paper pulp (PP) and Persea kurzii (PK) were used as non-chemical binders at ratios of 50:50, 60:40, 70:30, and 80:20. After mixing, all the samples were subjected to heat-free hydraulic compression at 5 bars to evaluate their physical, mechanical, thermal, and acoustic properties. Increasing the proportion of the binder directly impacted panel density and flexural strength while also inversely affecting porosity. The PK binder had a low thermal conductivity value of 0.040 W/mK, proving it was a good thermal insulator with a high sound absorption coefficient, especially at higher frequencies. The RSPP-4 panel had the highest noise reduction coefficient (0.51) and absorbed low frequencies, suggesting its potential for noise reduction. Microscopic analysis provided further insight into panel surface characteristics. PP exhibited a smooth surface with a continuous fiber weave that did not obscure the pores, while PK consisted of particles. The correlation between surface characteristics and acoustic performance, especially at high frequencies, underscored the intricate balance between material properties. Research results can be applied in the construction industry to develop sustainable building materials that offer superior thermal and acoustic properties. These thermal-acoustic panels can effectively utilize agricultural waste and show potential as environmentally friendly construction materials to enhance indoor comfort and acoustics in various building environments.