Thermal Management and Mechanical Properties of Epoxy‐Sandwich Composites Containing Microencapsulated Phase Change Material

In this work, epoxy (EP) foams containing 10, 20, and 30 wt% of microencapsulated phase change materials (PCMs) were developed as potential cores for multifunctional sandwich composites combining structural performance with latent heat storage capability. The foams were characterized for their microstructural, thermal and mechanical properties. Microstructural analysis revealed that PCMs dispersed within the cell walls and promoted an increase of open porosity. Despite these morphological changes, heat flow meter analysis confirmed that the foams retained enough insulating properties. Differential scanning calorimetry showed a melting enthalpy up to 36 J/g for a 30 wt% PCM content. Infrared thermography revealed a delay in their surface temperature during heating and cooling cycles, especially for a PCM content equal to or higher than 20 wt%. Flexural and compressive properties of the foams decreased with PCMs, regardless of the testing temperature. The foams were then used as core in sandwich composites. Mechanical tests showed improvements in core shear flexural strength (+37%), facing stress (+47%), and edgewise compression strength (+20%) at 20 wt% PCM. Therefore, 20 wt% PCM was found to be the most promising concentration for balancing the mechanical performance and the thermal buffering of multifunctional composites. The developed composites could have applications in aerospace, automotive, and refrigerated transportation industries.