Microencapsulation of n-Hexadecane as a Phase Change Material via In-situ Dispersion Polymerization: Effect of pH and Addition Rate of MF

Microcapsules containing n-hexadecane (HD) as the core and melamine-formaldehyde (MF) prepolymer as the shell material were prepared via in-situ polymerization and some parameters such as pH and addition rate of MF were invesigated as the affecting factors on the characteristics of the resulting microcapsules. The morphology and thermal properties of the microcapsules were studied using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA),respectively.The surface morphology of microcapsules showed almost a rough suface. From the DSC analysis it was concluded that for all samples, encapsulation efficiency of about 75-80% was obtained. It was shown by TGA that the profile of degredation severely depends on the reaction conditions. Both one-stage and two-stage degradation took place for different samples, but the second stage of degradation was above 300o C for all the samples.