Research On Phase Change Microcapsules With The Structure Of Acrylic Copolymer Shell And Paraffin Core

Building energy consumption plays a larger and larger part in the global energy consumption.The phase change energy storage technology,one of the most important measures to reduce building energy loss can be used in construction field.Because of its excellences:non-corrosive,chemical stability,high phase change latent heat,etc,Paraffin wax is becoming a hot spot in the study of phase change materials in recent years.Turning the paraffin into microcapsule,solve the problem of leak and phase separation that limit the application of paraffin,and widen the utilization of paraffin phase change materials in the domain of building energy efficiency.This paper studies the preparation of paraffin phase change microcapsules,and its application in functional putty.The primary contents are as follows:(1)A type of paraffin phase change microcapsules for thermal insulation of exterior wall was prepared through in-situ polymerization technique using 46#paraffin as core material and acrylic copolymer as shell.Moreover,the influence of core material and wall material weight ratio,emulsifier amount,polymerization reaction temperature and stirring speed of emulsion on the preparation and properties of the destination product were all studied.(2)The surface morphology,phase change properties as well as the thermal stability was respectively characterized by relevant analysis instruments.The results ultimately obtained showed that when the polymerization reaction temperature is 75? and under the condition of a mass ratio of core to shell of 1.8,the microcapsules prepared at the rotation speed of 1600 r/min with 8%emulsifier were particles of spherical shape.The average particle size is 0.68 pm and the surface is smooth.The phase change temperature was 47.8? and the Phase change enthalpy of the microcapsules was 174 J/g.(3)The paraffin phase change microcapsules obtained under the optimum synthesis condition were mixed into putty in different proportions.Then the relationship between the coefficient of thermal conductivity and dosage of microcapsule could be tested,as well as the ability of temperature control of the phase change putty.