A non-aqueous, heterogeneous polymerization process comprises heating a reaction mixture of about 5-70 %, preferably 10-30 %, by weight, of a vinyl monomer in an oil as solvent, and a free radical initiator, optionally in the presence of a crosslinking agent and/or a surfactant, wherein the oil solvent is present in an amount sufficient to keep the resultant polymer in a stirrable state throughout the polymerization. The polymer reaction product is capable of forming a uniform emulsion or gel upon addition of water thereto.