Formation of monodisperse poly(methyl methacrylate) particles by radiation-induced dispersion polymerization. II. Particle size and size distribution

Micron-sized poly(methyl methacrylate) particles were produced directly by radiation-induced dispersion polymerization in aqueous alcohol media using poly(N-vinylpyrrolidone) as a steric stabilizer at room temperature(10-35 degreesC). This method takes advantages of the specialities of radiation induction, and highly uniform polymer microspheres were obtained with high conversion. The gel effect was found from the polymerization kinetics curves. The number of nuclei produced in the early stage of the polymerization was found to be constant during the remainder of the polymerization. The effects of various polymerization parameters, such as irradiation dose rate, monomer concentration, stabilizer content, medium polarity, and polymerization temperature, on the particle size and the size distribution were investigated systematically.