Preparation and characterization of n-octadecane/poly(styrene–methyl methacrylate) phase-change microcapsule

Abstract

A phase-change energy storage microcapsule is prepared via emulsion polymerization, in which the copolymer of styrene (St) and methyl methacrylate (MMA) was used as shell material, n-octadecane as core material, sodium dodecyl benzene sulfonate (SDBS) as emulsifier. The morphology, phase-change thermal properties and thermal stability of microcapsule are characterized by particle size analyzer, transmission electron microscope, thermogravimetric analyzer (TG) and differential scanning calorimetry. The results show that the particle size of microcapsule is uniform, the dispersion of microcapsule particles is good, the microcapsule particles are well wrapped when poly(styrene–methyl methacrylate) copolymer (St/MMA = 1:5) is used as shell material, and SDBS content is 1.5 g (3% of the total mass). The initial temperature of exothermic peak is 31.9 °C, the termination temperature is 27.3 °C, the phase transition temperature is 28.9 °C, and the phase-change enthalpy is 48.39 J g−1. TG analysis shows that the long-term operating temperature of the microcapsule should not exceed 131 °C. IR analysis indicates that the obtained microcapsule contains core and shell material.