Preparation And Properties Of Paraffin Phase Change Materials

As a new functional material,phase change material(PCM)has been studied and applied in the fields of industry and agriculture,power electronics,architecture,textile and new energy with its unique performance advantages such as large latent heat,adjusting temperature range is suitable,saving resources and reducing pollution emission.In this paper,solid paraffin,solid liquid paraffin and two types of phase change materials are used.Low density polyethylene(LDPE),vinyl acetate(EVA)and ethylene-octene copolymer(POE)were coated to prepare two kinds of amorphous phase change materials suitable for different occasions.The differential scanning amount was observed by scanning electron microscope(SEM).The properties of the three systems were studied by means of thermal(DSC)analysis,leakage test,homogeneity test and durability test.The preliminary application of POE/solid paraffin fixed phase change composite was studied.The phase change insulation mortar was prepared by mixing it with cement mortar and its feasibility was studied.Using solid paraffin as phase change material,three kinds of resins with similar structure to paraffin(paraffin mixture),LDPE,EVA and POE,were used to study the encapsulation of paraffin.The latent heat of phase transition and phase transition temperature of each system were measured respectively.The mass loss rate,uniformity and durability above the melting temperature of paraffin wax are higher than those of the wax melting temperature.By comparing the main properties,it is concluded that the structure of LDPE and EVA is looser,the space is larger,the amount of paraffin is more,and the latent heat of phase change is higher than that of LDPE and EVA.The mass loss rate of POE/paraffin system was lower than that of EVA/paraffin system.The homogeneity and durability of POE are better than the other two systems.The effect of filler talcum powder and montmorillonite on POE coated paraffin phase change material was investigated.With the addition of two kinds of fillers,the package stability is improved,and the latent heat value is guaranteed,and the overall mass loss is reduced.Montmorillonite has better Adsorption capacity and stability than talcum powder.The POE matrix was used to encapsulate the solid liquid paraffin composite phase change material(CPCM).The results showed that:Compared with POE/paraffin system,the composite phase change material can satisfy the purpose of initial development,and the latent heat value is also higher in low temperature phase change materials,and the mass loss is small,and the composite phase change material has better durability.This kind of composite phase change material has good practical value.