1991 Volume 64 Issue 3 Pages 140-147
Microcapsules containing sodium polyacrylate of water-absorbent polymer were prepared by the drying-in-liquid method. First, sodium acrylate monomer was polymerized to some extent and W/O emulsion was prepared. Polymerization was continued after preparation of (W/O) /W emulsion. In this capsulation process, operational conditions, such as the conversion of monomer, the concentration of polystyrene as the wall material in oil phase and the impeller speed at the second emulsification, were changed stepwise. It was investigated how the operational conditions affected several properties of microcapsules such as the size distribution, the mean size, the content of core material, the rate of absorption and the amount of absorbed water. Also, the microscopic observation of the surface and the cross section of microcapsules was performed.
