Indoor functional plywood with electrothermal response, flame retardancy, and moisture-proof performance and enhanced surface temperature with nano-SiO ₂ film

Innovative wood-based composites have attracted considerable interest because of their potential applications in multifunctional indoor wood products. Flame-retardant electrothermal plywood (FR-Eplywood) with excellent Joule heat, flame retardancy, and moisture-proof performance was fabricated via a cold pressing process using carbon fiber paper as a heating element. The results showed that the bonding strength of FR-Eplywood in the air-dried state was 2.07 MPa. The FR-Eplywood exhibited outstanding low-temperature radiation performance and temperature uniformity, and the maximum temperature was 40.2°C and 57.9°C at 24 V and 36 V, respectively. Meanwhile, the flame retardancy performance was also significantly improved owing to the peak of heat release rate, and the total smoke release was reduced by 47.4% and 60.7%, respectively. Furthermore, FR-Eplywood can accelerate the discharge of water under low voltage. When the voltage was maintained at 36 V during 400 min of heating, the moisture content decreased from 26.8% to 1.7%, indicating that FR-Eplywood could inhibit mildew in humid environments through temperature management. This study provides a promising thermal management strategy for functional indoor wood products.