Thermal performance and flammability of phase change material for medium and elevated temperatures for textile application

Abstract

Thermal energy storage and insulation have potential applications in many fields such as incorporating phase change material (PCM) in textile materials for insulation in medium and elevated temperatures when the high heat flux 80–84 kW m−2 results from flashover conditions in a firefighting environment. The feasibility of four selected PCMs is considered in this research. The lack of guidance of hazards of sugar alcohols as a potential PCM is analyzed from molecular structure point of view. The results showed that isomerism of PCMs has a tremendous influence on the flash point of PCMs and hence flammability. Differential scanning calorimeter thermal performance showed that the four candidate PCMs have a remarkable melting temperature and enthalpy of fusion. Different heating rates were observed (1.11, 0.43, and 0.095 %) in the melting temperatures: at 50, 20, and 5 °C·min−1, respectively. Smaller heating rates are preferable for accurate data. PCMs also undergo degradation due to the high-temperature exposure. Although dulcitol and d-mannitol have the same molecular formula, dulcitol requires higher temperature for degradation than does d-mannitol, and this difference is around 26.08 K. The analysis of results showed that the position of functional group has tremendous influence on the thermal performance. Salt hydrates have a multistep thermal degradation and the lowest loss of mass compared with sugar alcohols. This is because salt hydrates have higher intermolecular forces, which make them undergo high thermal endothermic and exothermic processes.