The Preparation And Energy-saving Assessment Of A Phase Change Building Material

Intelligent and ecological is the inevitable trend of building materials development, forthe promotion of the building energy conservation of the state, and for the requirement of thecomfort of the built environment. New type of building materials with thermalstorage and thermoregulation function can be obtained by compositing phase changematerials and traditional building materials. It has large energy storage density andendothermic and exothermic under the constant temperature. It is able to maintain acomfortable environment effectively and reduce energy consumption and costs of buildingheating and cooling.In this paper, mircocapsules phase change material with polyurea resin as shell andn-octadecane as core were synthesized by interfacial polymerization, and the characterizationand performance were also discussed and systematic studied. By dry weight analysis method,the affect of monomer mass ratio of two shell materials, mass ratio of core and shell,the type and amount of emulsifier, emulsification stirring speed, and the reaction temperatureare studied. The results show the mircocapsules have better package effect, uniform particlesize and narrow particle size distribution when DETA:TDI=1:3, mass ratio of core and shell is1.95:1, emulsifier is OP-10(2.5g,2.04%of emulsion system), stirring speed is1000r/min andthe temperature is60℃.FT-IR、TG、DSC and nano-particle size analyzer are used to characterize the phasechange material under optimal conditions. The result of FT-IR shows the core material issuccessfully wrapped by the shell. The result of TG shows the mircocapsules decompose at150and230℃. The shell has a certain blocking effect on the volatilization of the corematerial. The result of DSC shows the phase change temperature is27.30℃, the enthalpy is95.66kJ/kg, and the parcel rate is72.15%. The result of particle size analysis shows theparticle size is between1μm~7μm when the stirring speed is1000r/min, the average particlesize is3.5μm.As for the visual inspection of the energy-saving effect of MicroPCM, theevaluation from a macro perspective is undertaken. Coating glass is prepared bycompounding mircocapsules phase change materials and paint, and a wooden model room isbuilt with it. The temperature data of the model room is collected under infrared light. Theresult shows the building materials with mircocapsules phase change materials canslow down the external temperature changes in the environment. The maximum of peak temperature difference is1.70℃and the maximum of energy efficiency is27.56%. Theenergy-saving effect is considerable. The evaluation mechanism in this paper is practical andeffective for verifying the energy saving effect of MicroPCM.