Thermal comfort and flame retardant performance of novel temperature-control coatings with modified phase change material microcapsules

Organic phase change material (PCM) is considered to be promising for building energy efficiency, as it can be directly incorporated into matrix resin to impart thermal storage capacity after being encapsulated in a shell to form phase change material microcapsule (EPCM). However, existing studies have shown that the encapsulation of organic shell materials negatively affects the inherent thermal storage efficiency of PCM and increases its fire hazard. Towards efficient utilization of the thermal storage efficiency of organic PCM and reduction of its fire hazard when applied to building insulation coatings, we decorated halloysite nanotube (HNT) with P, N component (p-HNT) and embedded it into EPCM (p-h-EPCM), which integrated the high thermal conductivity and flame retardancy of p-HNT and developed a high-performance EPCM for thermal regulation coatings. Specifically, p-h-EPCM possesses exceptional thermal stability and has an enthalpy of 113.21 J/g. After mixing ph-EPCM into epoxy resin (EP/p-h-EPCM), we further investigated its flame-retardant effect and temperature control performance in practical applications. The cone calorimeter (CCT) showed that EP/p-h-EPCM was 35.7 % lower in the peak of heat release rate (pHRR) and 18.97 % lower in the total heat release (THR) compared to the epoxy resin (EP) that incorporated the same mass of EPCM (EP/EPCM). Moreover, the small room test and thermal imager test results showed that EP/p-h-EPCM had the mildest temperature fluctuations of 8.68 degrees C and 5.23 degrees C when heating/cooling, respectively. Considering the favorable flame retardant effect and energy-efficient thermal regulation performance, the obtained p-h-EPCM has a broad prospect in the practical application of building temperature-control coatings.