Multifunctional wood composite with integrated phase change material for energy harvesting, self-healing, flame retardancy, and recycling

Oriented strand boards have been widely used as sheath for roofing or dry walls in residential buildings. Residential buildings account for a large portion of energy consumption. Therefore, an oriented strand board with energy harvesting capability is highly desired. In this study, we prepared an oriented strand board by constructing sandwich structures. The face sheets of the sandwich are made of short wood fiber reinforced shape memory vitrimer with flame retardancy. The core of the sandwich is made of form-stable phase change material by impregnating paraffin wax into an open-cell polyurethane foam. Comprehensive characterizations were conducted on the sandwich composite. Key results demonstrated that the wood composites exhibited high mechanical strength, effective thermal regulation, complete delamination healing and penetration hole closing, and excellent recyclability. A model house was simulated to quantify energy absorption by the composite during the summertime, showing substantial thermal energy absorbed through the latent heat.