Study on properties and phase transformation mechanism of oil-based solid-solid phase change materials

Polymeric solid-solid phase change materials (PSSPCMs) can essentially solve the leakage problem of physically composited solid-solid phase change materials, but the phase change enthalpies, which are usually far lower than the theoretical values, limit their applications. In this work, three PSSPCMs were prepared by co-esterification and polymerization with different amount of stearic acid (SA). The PSSPCMs suffered from lower crystallinities and activation energies at transition than pure SA, indicating that confinement of polymeric network on crystalline domains may lead to the decrease of enthalpy. According to analysis from generalized two-dimensional correlation Fourier transform infrared, the polymer network confinement in PSSPCMs mainly restricted the vibrations of nu asCH3, nu CH, and nu sCH3. In-depth understanding of the interaction between the crystalline chains and the polymeric networks would be beneficial for molecule design of novel PSSPCMs with high enthalpy.