Synthesis, thermal properties and thermal reliabilities of microspheres with ester mixtures as phase change materials

Using suspension-like polymerization method, a series of microspheres with ester mixtures as phase change materials were prepared. Thermal properties of the binary mixtures like, paraffin/butyl stearate, paraffin/octadecyl methacrylate, and paraffin/dodecyl 2-methylacrylate, and ternary mixtures, like paraffin/butyl stearate/octadecyl methacrylate and paraffin/butyl stearate/dodecyl 2-methylacrylate, were investigated. The phase change temperature of these binary and ternary systems could be adjusted by regulating the composition of them. SEM photographs showed that these microspheres have spherical profiles and compact surfaces with diameter ranging from 10 to 80 mu m. DSC results indicated that the melting enthalpy of these microspheres ranging from 30 to 65 J/g. Moreover, after being subjected to thermal-cycling test for 500 times, these microspheres kept good thermal performances and reliabilities.