Effect of the amounts of calcium carbonate encapsulated by polystyrene through in-situ emulsion polymerization on the thermal properties of the resulting polystyrene

Calcium carbonate encapsulated by polystyrene matrix was obtained by dropping a solution of potassium carbonate into the emulsified solutions of styrene and aqueous calcium chloride by non-ionic surfactants. Thermal properties of these materials with the amounts of calcium carbonate were investigated by DSC and TGA. The surface of calcium carbonate was observed by SEM, and crystal structures of calcium carbonate encapsulated by polystyrene was investigated using XRD. From these results, the increase of T-g of polystyrene encapsulating calcium carbonate was ascribed to the change of crystal structure of calcium carbonate from vaterite to calcite.