The semicontinuous emulsion copolymerization of vinyl acetate: dibutyl maleate (60:40, vol/vol) was carried out at different co-emulsifier distributions between initial reactor charge and continuously introduced monomer. The overall conversion, the co-polymer particle size, and the properties of films obtained from emulsions were determined experimentally. Polyvinyl alcohol and cetyl alcohol ethoxylated with ethylene oxide (20 moll were used as protective colloid and coemulsifier, respectively. Experimental investigations have shown that the unreacted monomer concentration and the copolymer particle size oscillate with time. These oscillations are related to a tendency for limited particle flocculation.