Preparation and Characterization of Divinylbenzene based Capsule Encapsulated Octadacane: Monomer Droplet Generated by Phase Inversion Emulsification

Abstract

This research was aimed to study the preparation of poly(divinylbenzene)-/octadecane (PDVB/OD) and poly(divinylbenzene-methylmethacrylate)/octadecane (P(DVB-MMA)/OD) microcapsules by microsuspension polymerization using phase inversion emulsification (PIE) for monomer droplet generation. In the first step, PDVB/OD microcapsule was prepared using PIE for the oil droplets generation. The influence of the surfactant type and amount with and without co-surfactant on the colloidal stability, particle size and size distribution of microcapsules were investigated compared with the conventional emulsification technique. In the case of PIE, the microcapsules size about 1.5 μm with narrow particle size distribution (PSD) and good colloidal stability throughout the polymerization were obtained using polyvinyl alcohol and sodium dodecyl sulphate as the surfactant and cosurfactant, respectively. On the other hand, the coagulation was observed using conventional technique with the same recipe of PIE. In the second step, MMA was introduced to the copolymer microcapsule to improve the latent heats of the encapsulated OD. The influence of the additional rate of the aqueous phase and the monomer ratio were studied. At the additional rate of 2 mL/min, approximately 4 μm microcapsule with narrower PSD and higher colloidal stability than the other conditions were obtained. The increase of MMA content from 50 to 70 wt % increased latent heats of the encapsulated OD due to high phase separation of P(DVB-MMA) shell and OD core. From the results, it can be concluded that PDVB/OD and P(DVB-MMA)/OD microcapsules were successfully prepared by microsuspension polymerization using PIE for oil droplet generation.