Comparative Studies of Phase Change Characteriatics of PET-PEG Copolymer and PET/PEG Blend

摘要

PET-PEG copolymer and PET/PEG blend were prepared as Phase-Change Materials (PCMs). Their phase change characteristics were tested. Both of the samples exhibited two melting peaks and two crystalline peaks in the heating and cooling process. The melting peak and crystalline peak of PEG segments appeared in low-temperature area(lower than 52℃), can be used for heat-storage. The phase change enthalpy of PEG segments of copolymer was about 10 J/g higher than that of blend. For PET-PEG copolymer, the chemical bonding strength is strong enough to ensure that PEG is detached, so even above the melting temperature of PEG, the material still remains in the solid state. In contrast, for PET/PEG blend, at high temperature the amorphous PEG can migrate freely and leak from the blend, then the blend loses phase change characteristics.