Preparation and characterization of polyurea microencapsulated phase change material by interfacial polycondensation method

•Polyurea/paraffin microencapsulated phase change materials were prepared.•Isophorone diisocyanate and ethylene diamine were used as shell monomers.•The phase latent heat of the MicroPCMs is 92.5 J/g with 44.5% core content.•The MicroPCMs with the core/shell ratio of 75/25 have good compactness and stability.

Phase change materials (PCMs) for heat energy storage have received an extensive attention in recent years. For heat energy storage application, a new type of polyurea (PU) microencapsulated phase change materials (MicroPCMs) were prepared by interfacial polycondensation method with isophorone diisocyanate (IPDI) and ethylene diamine (EDA) as shell monomers and paraffin as core material. The influences of monomer mass ratio, emulsifier type, emulsifier dosage and emulsifying stirring speed on MicroPCMs were investigated systemically. The morphology, chemical composition and particle size distribution of the MicroPCMs were characterized by using scanning electron microscope (SEM), fourier transform infrared (FT-IR) spectrum and laser particle size analyzer respectively. The results show that the MicroPCMs prepared under the optimal conditions have spherical shape and an average diameter of 2.42 μm. The results of differential scanning calorimeter (DSC) analysis show that the phase latent heat of the MicroPCMs is 92.5 J/g with 44.5% core content. The results of anti-osmosis test confirm that the MicroPCMs with the core/shell ratio of 75/25 have good compactness and stability. The microencapsulation technology developed is expected to be used in air conditioning, heating and other fields.

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