Study On Synthesis And Properties Of Fatty Acid/Alcohol Binary Eutectic Composite Phase Change Material

Due to the advantages of phase change energy storage materials,such as high energy storage density,low undercooling and strong thermal stability,phase change energy storage materials technology can effectively solve the problem of energy use without periodicity,continuity and instability.In this paper,the synthesis of lauric-myristic acid/activated carbon,lauric-myristic acid/nano-silica,hexadecanol-palmitic acid/polyvinyl butyral/activated carbon composite phase change materials were studied,and its microscopic morphology,crystal structure,phase change performance and thermal stability performance are analyzed and tested.With lauric acid（LA-MA）eutectic as the phase change material and activated carbon（AC）as the carrier,composite phase change materials with different mass ratios were prepared by the porous media adsorption method.The properties and microstructure of LA-MA/AC composites were analyzed by various characterization methods.The results show that the composite process of LA-MA eutectic and AC is a simple physical mixing process,and no new chemical bonds have been found.The melting temperature,freezing temperature and enthalpy of the samples were determined by differential scanning calorimetry（DSC）.The melting and freezing temperatures of LA-MA eutectic are 32.42℃and 33.63℃,and the melting enthalpy and freezing enthalpy are 152.64 J/g and 148.8 J/g,respectively.The thermal stability of the LA-MA eutectic was significantly improved by adding AC as the carrier material.The research results can be used as a reference for solar energy storage applications.A novel lauric acid myristic acid/nano silica（LA-MA/nano-Si O₂）shape stable phase change material was prepared by melt blending method.The thermal properties and microstructure of the composites were investigated by FT-IR,XRD,SEM,DSC and TGA.The melting and freezing temperatures of LA-MA eutectic are 32.42℃and33.63℃,and the melting enthalpy and freezing enthalpy are 152.64 J/g and 148.8 J/g,respectively.Adding AC as the carrier material,the thermal stability of LA-MA eutectic is obviously improved.The results can be used as a reference for the application of solar energy storage.A new type of shape stable phase change material,hexadecanol palmitic acid/polyvinyl butyral（hd-pa/PVB）,was prepared by solvent evaporation method,and activated carbon was added as the modified material.The results of liquid leakage test show that the optimum mass ratio of hd-pa eutectic mixture and PVB is 6.5:3.5.The results show that the latent heat of phase transformation is 104.02j/g and the phase transformation temperature is 36.37℃when the content of activated carbon is 15%.DTG and TGA results show that the addition of activated carbon can enhance the thermal stability of hd-pa/PVB composite phase change materials,and has good thermal stability at 45℃,which has a good application prospect in the field of waste heat recovery.