A phase-change stored energy microcapsules were prepared by polymerization

in which polystyrene (PS)

poly methyl methacrylate (PMMA) or copolymers of styrene and methyl methacrylate were used as shell materials

n-octadecane was used as a core material

and sodium dodecyl benzene sulfonate (SDBS) as a emulsifier. The morphology

phase-change thermal properties and thermal stability of microcapsules

respectively

were characterized by particle size analyzer

transmission electron microscope (TEM)

thermogravimetric analyzer (TG) and differential scanning calorimetry (DSC). The results show that the particle size of microcapsules is uniform

the particle dispersion is good

and the shell is well wrapped when the copolymer of styrene (St) and methyl methacrylate (MMA)

both mass ratio is 1:5)

is used as shell material

and sodium dodecyl benzene sulfonate content is 1. 5g (3% of the total mass). The heat release peaks of microcapsules are at 27. 3℃ of starting temperature

at 31. 9℃ of end temperature

and the phase transformation temperature is 28. 9℃

the phase-change enthalpy of microcapsules is 48. 4J/g. Long-term use temperature should not exceed 131℃ by TG analysis. The microcapsules contain core and shell materials by IR analysis. This octadecane/poly (St- MMA) phase change microcapsules can be used for the material