By a semicontinuous emulsion polymerization method with a variable monomer feed rate, a terpolymeric latex of methyl methacrylate and ethyl acrylate functionalized with methacrylic acid was synthesized. Conversion and reactor temperature vs. time were followed during the reaction. Characterization of the latex system was performed by particle-size measurements, scanning electron microscopy, infrared spectroscopy, viscometric molecular weight, glass transition temperature measurement, and theological behavior.