Polysiloxane-Modified PMMA-Shell Phase Change Microcapsules for Thermal Management Fabrics

Critical issues such as leakage, degradation, and thermal response hysteresis have become the focus in the application of phase change materials (PCMs) in area such as thermal management of fabrics. The encapsulation of PCMs prepared as microcapsules using polysiloxanes, etc. as a component unit of crosslinking agents represents a highly promising avenue of research. In this work, organosilicon crosslinkers are prepared and employed for the crosslinking of poly (methyl methacrylate) (PMMA) for microencapsulation of paraffin wax in microcapsule phase change materials (mPCMs). The results showed that increasing the degree of crosslinking helps to improve the performance of mPCMs by smoothing the shell surface, but excessive crosslinking leads to flocculation, which reduces its performance. The mPCMs produced with 10% wt crosslinking agent gave the highest performance with encapsulation efficiency, melting enthalpy and crystallization enthalpy of 81.3%, 285.0 J g^-1 and 253.1 J g^-1, respectively. The obtained mPCMs are also combined with epoxy resin and fabrics to form composite materials. Notably, the polysiloxane-modified mPCMs permit epoxy resins to achieve a maximum temperature reduction of 25 °C. By adjusting the mass ratio of organosilicon crosslinkers, the obtained mPCMs enable textiles to reach a maximum temperature reduction of 17 °C while maintaining satisfactory air permeability.