Multifunctional sandwich composites with optimized phase change material content for simultaneous structural and thermal performance

This work aims at developing novel multifunctional sandwich composites with optimized thermal energy storage and structural load-bearing performance by incorporating microencapsulated phase change materials (PCMs) into polyurethane (PU) foam cores. The optimized foam containing 20 wt% PCM, balancing good latent heat storage (up to 29 J/g) with low thermal conductivity (up to 0.035 W/(m·K) at 50 °C), was used to produce sandwich panels with high-performance epoxy/carbon fiber laminate skins. Microstructural characterization confirmed excellent interfacial adhesion between the core and skins. The multifunctional panels exhibited comparable flexural strengths (150 kPa) and facing stresses (25 MPa) to neat PU sandwich controls. By integrating thermal regulation from PCM phase change with structural reinforcement from the sandwich architecture in a single multifunctional material system, this work contributes to the development of lightweight, energy-efficient composite materials suitable when weight reduction and thermal management are paramount, such as in aeronautics and cold chain logistics.