Series of solid-solid phase change materials with ultra-high thermal stability and controllable phase change temperature: kilogram-leveled preparation and application investigation

Abstract Phase change materials (PCMs) have shown great performance in the fields of thermal energy storage and thermal management due to their passive yet high-efficient temperature control and thermal energy storage properties. However, conventional physically-blended composite PCMs remain problematic, because the leakage and shape deformation phenomena cannot be ignored in engineering applications with kilogram-leveled usage. Here we develop a methodology to prepare a series of solid-solid PCMs (SSPCMs) with great thermal stability and controllable phase change temperature (PCT) via free radical polymerizations. The simplest one-pot synthesis strategy allows the kilogram-leveled preparation for engineering demands. The obtained novel SSPCMs with 3-dimensional main chain and alkyl side-chain demonstrate excellent thermal stability that can withstand the heat-erosion up to 250°C without any leakage or deformation. Furthermore, the PCT region of the SSPCMs can be easily tailored in a wide range from 9.7 to 65.3°C by carefully selecting the alkyl acrylate monomers with different carbon atoms on the ester group. After simply incorporating with expanded graphite (EG), the resultant EG/SSPCMs with well-defined PCT region present excellent performance in various applications, including building energy conservation, battery thermal management and waste heat recovery. Profiting from the controllable PCT coupled with the great thermal stability, we believe that this series of SSPCMs would demonstrate huge potentials in more expanded industrial fields by further tailoring their PCT to a wider range.