Development of low-carbon biocomposite from rice husk waste fiber for thermal insulation in climate-adaptive buildings

The escalating impacts of climate change on indoor environments have intensified the need for climate-adaptive, low-carbon building materials that enhance thermal resilience and energy efficiency. Conventional insulation materials remain heavily dependent on non-renewable resources and often fail to adequately respond to dynamic thermal loads and sustainability targets in climate-resilient building design. This study aims to develop and optimize rice husk (RH)-based biocomposite panels using polyvinyl alcohol (PVOH) as a binder to improve thermal insulation and mechanical performance for building applications. RH-PVOH biocomposites were fabricated via hot-press molding with varying binder contents (0–15 wt%) at a controlled density of 0.8 g/cm³. The composites were systematically evaluated for hygroscopic behavior, mechanical strength and thermal conductivity. The results show that PVOH incorporation significantly enhances composite performance. At 10% PVOH, the biocomposite exhibited low moisture absorption and thickness swelling while achieving the highest specific flexural strength at 12.27 MPa, tensile index strength at 5.46 MPa and impact strength at 2.69 kJ/m². Thermal conductivity was obtained at 0.245 W/m·K, indicating improved insulation efficiency. These enhancements are attributed to improved fiber-matrix bonding, reduced porosity and better microstructural uniformity. In thiswork, the developed RH-PVOH biocomposite at 10% PVOH content demonstrates strong potential as a low-carbon, climate-adaptive insulation material for resilient indoor environments. This finding supports energy-efficient building strategies by enhancing thermal performance and contributing to improved indoor environmental quality under changing climate conditions.