Preparation And Properties Of Polyethylene Glycol-Based Thermally Conductive,Elastic And Shape-Shapilized Phase Change Materials

Thermal energy storage（TES）technology can improve the energy efficiency and achieve the required thermal energy regulation,as well as phase change energy storage technology is its research hotspot.Phase change materials（PCMs）developed by phase change energy storage technology have been extensively studied for their ability to absorb heat through latent heat and release stored energy into the environment.Leakage and heat transfer of PCMs in applications are the key to research,so the enhancement of their ability to prevent leakage and heat transfer is particularly important.Encapsulating PCMs in a polymer substrate or shaping it is an effective method to prevent leakage of PCMs.Polymer materials can adjust the mechanical properties of PCMs,and porous materials can improve the thermal conductivity of PCMs.The polymer material can be used as an interface material between the device and the heat sink to play the role of shock absorption and heat dissipation.Selecting thermally conductive porous materials can improve the thermal conductivity of PCMs.The main contents of this paper include:（1）In this paper,polyethylene glycol 2000 is used as PCMs.GO/CNTs aerogels（GCA）obtained by self-assembly of graphene oxide（GO）and carbon nanotubes（CNTs）,which are used as porous materials to prepare thermally conductive shape-stabilized phase change materials（TSPCMs）PEG/GCA.The effects of different ratios of GO and CNTs on the thermal conductivity and permeability of PEG are discussed.The results show that compared with graphene aerogel（GA）,CNTs have a synergistic effect on enhancing thermal conductivity of TSPCMs.When the mass ratio of GO and CNTs is 2:1,the thermal conductivity of PEG/GCA(PGCA_2/1)is the highest,0.76 W·m^-1·K^-1,and the overall performance is well.（2）By in-situ polymerization,PEG is encapsulated in a P（MMA-BA）three-dimensional crosslinked network structure to obtain elastic shape-stabilized phase change materials（ESPCMs）.Among them,the latent heat storage capacity of ESPCMs is related to the PEG content,and the hardness increases with the increase of the PEG content,as well as has a relatively low leakage rate.The monomer ratio has the greatest effect on the hardness of ESPCMs,and when the mass ratio of MMA and BA is 5:5,the hardness of ESPCMs is lower than that of pure PEG.Taken together,when the PEG content is 50%and the monomer ratio is 5:5,the ESPCMs obtained have a higher latent heat value,a lower leakage rate,and a certain elasticity.（3）PEG and polymer monomers are filled into GCA_2/1 by vacuum-assisted impregnation and in-situ polymerization to obtain thermally conductive and elastic shape-stabilized phase change materials（TESPCMs）.When the PEG content is 50%,the minimum error between the enthalpy and theoretical value of the sample is only-0.8%,the thermal conductivity reaches a threshold of 0.65 W·m^-1·K^-1,and it has a certain elasticity.The leakage rate of TES-50 is 1.41%,which is 90.74%lower than PGCA_2/1,and 23.78%lower than ES-50 that achieves the purpose of optimizing the anti-seepage performance and has excellent comprehensive performance.