Study on transition characteristics of PEG/CDA solid–solid phase change materials

New kinds of solid–solid phase change materials (PCMs) with netted structure have been prepared. In these new materials, the rigid polymer cellulose diacetate (CDA) serves as skeleton, and the flexible polymer polyethylene glycol (PEG) serves as functional branch chain. The transition mechanism of these functional polymers is the transfer between the amorphous and crystal states of the PEG. During the transition, PEG gives or takes in latent heat, and at the same time, the whole composite always remains in the solid state. The series experiments show that the PCMsʹ latent heats, phase transition temperatures and mechanical strengths depend on the molecular weights and weight percentages of PEG.