Preparation And Properties Of Comblike Polyether Based Composite Phase Change Materials

As a non-toxic and environmentally friendly solid-liquid phase change material,polyethylene glycol?PEG?has a strong thermal storage capacity by storing or releasing heat energy on the phase change process,but it has the following problems in its practical application.?1?When the ambient temperature is higher than its phase change temperature,the PEG will change from solid to liquid,so that liquid leakage occurs.The researchers generally combine it with the support material to give it shape stability before and after phase change,but the support material usually reduce the thermal storage density of the composite due to the lack of phase change properties;?2?Its thermal conductivity is small,resulting in slow thermal transfer in the phase change process and low thermal storage and release efficiency.In order to solve the above problems,the paper designs a solid phase change material with phase change thermal storage characteristics as a supporting material,and loads solid-liquid phase change material to obtain high latent heat phase change energy storage material.In order to improve the thermal conductivity of the composite phase change material and the thermal storage and release rate of the composite phase change energy storage material,the thermal conductivity enhancers are directly doped.Through the free radical polymerization of Poly?ethylene glycol?methyl ether methacrylate?mPEGMA?,the in-situ loading of PEG was achieved.The PEG/PPEGMA composite form-stable phase change material was obtained.The form-stable effect of PEG/PPEGMA composite form-stable phase change material was tested by changing the content of PEG.The tested result showed that optimum mass ratio of PPEGMA to PEG was3:1.The crystallization properties,phase change heat storage properties and stability of PEG/PPEGMA materials were investigated by X-ray diffraction analysis?XRD?,differential scanning calorimetry?DSC?and thermogravimetric analysis?TG?.The obtained PEG/PPEGMA composite forn-stable phase change material has good crystallinity and thermal stability,and the phase change enthalpy of 75%PEG6000/PPEGMA phase change material reaches 200.3 J/g.PEG/PPEGMA/Ni composite form-stable phase change energy storage materials were prepared by impregnation-free radical polymerization.The phase change latent heat of the material is 140.7 J/g.Compared with PEG/PPEGMA phase change material,its thermal conductivity reaches 0.57 W·?m·K?^-1,which is 128%higher than PEG/PPEGMA composite phase change material,and PEG/PPEGMA/Ni material has good performance of thermal stability.PEG/PPEGMA/GO composite form-stable phase change energy storage materials were prepared by blending method with graphene oxide?GO?as thermally conductive reinforcing material.When the GO content is 5%,the phase change enthalpy of the composite form-stable phase change material is 156.4 J/g,and the thermal conductivity is improved by104%compared with PEG/PPEGMA.PEG/PPEGMA/GNs composite form-stable phase change energy storage materials were obtained by direct doping method using graphene?GNs?to improve the thermal conductivity.The test results show that the PEG/PPEGMA/GNs composite phase change energy storage material has good form-stable effect and crystallization performance.When the GNs content is 5%,the phase change latent heat of the material is 164.4 J/g.Compared with PEG/PPEGMA material,the thermal conductivity is increased by 160%.The PEG/PPEGMA/GNs composite phase change energy storage material achieves high heat storage ability,and the thermal conductivity of the composite material is also significantly improved.