Super-elastic and shape-stable solid-solid phase change materials for thermal management of electronics

Solid-solid phase change materials (SSPCMs) have become the preferred materials in thermal management of electronic devices because their inherent properties of maintaining constant temperature in the process of heat absorption and heat release. However, the defects of the poor mechanical properties, thermal stability and recyclability are still limiting the development of SSPCMs. Although there has been a large amount of reports to construct flexible composite PCMs, flexible SSPCMs with excellent tensile properties still remain little attention. Herein, we construct a SSPCM film with outstanding shape-stable property and super elastic for electronics thermal management. Notably, through adjusting the molecular weight of PEG to change the phase transition enthalpy and temperature of PU, which is also equipped with long-term cycling stability after 700 thermal cycles and significant shape foldability and stretchability. What’ more the elongation at break and enthalpy of as-obtained PCM can reach to 420% and 61.48J/g, besides the reason behind its excellent tensile performance is revealed by molecular dynamics simulation. Besides, the super elastic flexible SSPCMs developed in our work are existing great potential for new generation flexible thermal management of electronics and wearable devices.