Preparation And Properties Of A Series Of Novel Shape-stable Phase Change Materials

In order to reduce the consumption of fossil fuels and improve the utilization rate of energy,many methods have been adopted.Among them,the energy economy of the thermal energy storage system is an important means to alleviate the consumption of fossil fuels.The high latent heat of phase change materials（PCMs）can realize the storage and release of large amounts of thermal energy,making it have great development potential.Compared with inorganic materials,organic PCMs have many advantages,such as good stability,high repeatability,phase-free separation and supercooling.Therefore,organic solid-liquid PCMs（SLPCMs）among organic PCMs has been widely investigated.However,the leakage problem during the phase transition of SLPCMs limits the widespread use of SLPCMs.To overcome this inherent leakage problem,in this work,hexadecyl acrylate（HDA）was used as the phase change matrix because its phase transition temperature is within the human comfort range without supercooling properties.Allyl glycidyl ether（AGE）and 4-acryloxy benzophenone（ABP）was introduced into the polymer by free radical polymerization（FRP）without solvent to obtained block copolymers with epoxy groups and ketone groups（sensitive to UV）,shape-stable phase change material（SSPCM）was fabricated based on epoxy cross-linking and UV cross-linking.The leakage problem of the phase-change matrix in the period of usage is solved by using the cross-linking network of phase change matrix.The main contents are summarized as follows:（1）A series of block copolymers PHDAAs with different epoxy groups contents were successfully fabricated using FRP method,and SSPCMs was obtained by using DETA as cross-linking agent and named as SPHDAAs.The melting onset temperature(T_mo),crystallization onset temperature(T_co),melting enthalpy（?H_m）and crystallization enthalpy（?H_c）of PHDAA-5（the mass ratio of AGE and HDA is 5:95）are 32℃,29℃,86 J/g and 86 J/g,respectively.（2）Based on PHDAAs,a series of SSPCMs,called SPHDATs,were obtained by using polyetheramine（ATPE）as a crosslinking agent.Compared with SPHDAAs,although the thermal properties and thermal stability of SPHDATs are similar to those of SPHDAAs,the raw materials used in SPHDATs are safer,more environmentally friendly,and have a longer curing time.The extension of the curing time provides a better guarantee for possible post-processing procedures in practical applications such as high-temperature spinning.The T_mo,T_co,?H_m and?H_cof the sample PHDAT-5（the mass ratio of AGE and HDA is 5:95）are 31℃,28℃,83 J/g and 83 J/g,respectively.（3）Using FRP method,a series of block copolymer PHDABs with UV-sensitive ketone groups were fabricated.After UV irradiation treatment,a series of SSPCMs were obtained,denoted as SPHDABs.The application of UV cross-linking method greatly improves the fabrication efficiency and provides more possibilities for practical applications.The T_mo,T_co,?H_m and?H_c of the sample PHDAB-1.5（the mass ratio of ABP and HDA is 1.5∶98.5,UV irradiation treatment 10 min）are 32℃,29℃,57 J/g and 58 J/g,respectively.