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

New kinds of solid-solid phase change materials (PCMs) with netted structur e have been prepared. In these new materials, the rigid polymer cellulose d iacetate (CDA) serves as skeleton, and the flexible polymer polyethylene gl ycol (PEG) serves as functional branch chain. The transition mechanism of t hese 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 sta te. The series experiments show that the PCMs' latent heats, phase transiti on temperatures and mechanical strengths depend on the molecular weights an d weight percentages of PEG. (C) 2001 Elsevier Science Ltd. All rights rese rved.