Coated polymer thickness in encapsulation process of inorganic powder with heterogeneous polymerization.

The encapsulation of a fine inorganic powder with polymer was carried out by heterogeneous polymerization of methylmethacrylate in water in the presence of powder. The effect of methods of monomer addition on the encapsulation state and coated polymer thickness was investigated experimentally. The encapsulation state with polymer was influenced remarkably according to methods of monomer addition. The thickness of coated polymer increased with an increase in the amount of monomer added. The addition of monomer continuously or little by little to the reaction system and keeping the concentration being less than the saturated solubility was found to be effective to increase the thickness of coated polymer.