Study On Preparation And Properties Of Phase Change Polyester Materials

Phase change materials(PCM)are the materials which can store heat and adjust temperature by phase change process.In this paper,polyethylene glycol(PEG) was selected as the phase-change substance,and PBT,which has a lower melt point compared with PET,was selected as matrix.By DMT synthesis route,we got a series of polybutylene terephthalate(PBT)-polyethylene glycol(PEG)copolymers.The results were shown as followed:By polymerizing,we can get PBT-PEG copolymer which has definite solid-solid phase-change characteristic.The phase-change characteristics of the copolymers strongly depend on the molecular weight of added PEG.Only copolymerized with PEG of molecular weight higher than 4000,the PBT-PEG copolymer would show definite phase-change characteristics,and the phase-change characteristics of the products would vary with the change of proportion of PEG/DMT,The proper proportion of PEG is believed between 45 percent and 55 percent.Meanwhile,the PBT/PEG blending composite has been proved that it doesn't have the solid-solid phase-change characteristics.With the increasing amount of PEG which is added to copolymer,the thermal crystal temperature of PET segments shift to higher temperature while Tc of PEG shifts to lower temperature.It has been proved that the copolymer is block-copolymer with hard block end through the FTIR and NMR testing.The copolymerization between PBT and PEG has...