Characterization and optimization of thermal properties of rice straw and Furcraea foetida fiber reinforced polymer composite for thermal insulation application

The majority of the materials used in the building insulation are non-biodegradable polymeric materials. The continuous use of these polymers will not only cause environmental pollution but can also trigger health hazards in living beings. Therefore, in this study a sustainable composite material is prepared to limit the consumption of polymers by reinforcing them with rice straw agro-wastes and Furcraea foetida based natural fibers. The thermal stability, conductivity, transmittance, resistance, specific heat capacity and the flammability properties of the fabricated composite are evaluated. It is observed from the study that the composite with 20 wt% of rice straw showed the lowest thermal conductivity of 0.128 W/m ^oC which is 29.67% lower compared to neat epoxy material and was thermally stable up to 248 °C. Also, the thermal transmittance of the composite was reduced by 29.66% and it showed a thermal resistance of 0.154 m^{2 o}C/W at a temperature of 70 °C. The composite with the highest concentration of rice straw showed maximum specific heat of 3.22 J/g ^oC and it showed lower flammability with an average burning rate of 5.67 mm/min. The hybridization of composite with rice straw (15 wt%) and Furcrea foetida (20 wt%) fiber improved the strength of the composite and also it showed thermal conductivity of 0.132 W/m ^oC and was thermally stable up to a temperature of 272 °C.