Preparation And Performance Analysis Of Phase Change Material Microencapsulated By Urea-formaldehyde Resin Modified By Melamine

The microencapsulated phase change material was prepared using n-hexadecane as core material, urea formaldehyde resin modified by melamine as composite wall material by in situ polymerization. The influences of factors, including reaction temperature, curing PH, ratio of core material and wall material, and proportion of melamine, on microencapsulation rate and microencapsulation efficiency were investigated by single-factor experiments.And microcapsules prepared under various reaction conditions were tested formaldehyde content to obtain low formaldehyde content of the microcapsules, getting a secure,high fever enthalpy of phase change microcapsules. The properties of microcapsules, such as structures, appearance shape, thermal stability, enthalpy and other properties, were characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TG), differential scanning calorimetry (DSC). Experimental results showed that:when the condition of microcapsules prepared were the reaction temperature of 45 ℃, curing PH of 2.5, ratio of core material and wall material of 1.5:1 and proportion of melamine of 30%,The prepared microcapsules were spheric morphology, whose average particle size was 15-20μm, surface was ragged, but the density was good,encapsulation efficiency was 53.47%, enthalpy was 122J/g, thermal stable temperature was 170℃,formaldehyde content was 0.278g/kg which was complied with EU safety standards on formaldehyde.Therefore, this paper obtained a high thermal enthalpy of security phase change microcapsules under the above conditions..