GENERATION OF SPHERICAL AND MONODISPERSE PARTICLES OF POLY(STYRENE) AND POLY(METHYL METHACRYLATE) BY ATOMIZATION OF MONOMERS AND DISSOLVED POLYMER PRECURSORS

A technique to produce spherical and monodisperse particles of selected polymers is presented. Liquid precursors of either mixtures of organic monomers and initiator catalysts or polymers dissolved in organic solvents were sprayed inside a vertical thermal reactor. The temperature range in the reactor was 400-670 K and the experiments were conducted in a nitrogen atmosphere. Atomization was achieved by an acoustically excited aerosol generator. Batches of equal size particles of two thermoplastic materials, poly(styrene) and poly(methyl methacrylate), were obtained in the range of 30-60-mu-m in diameter. Elemental analysis showed that the C and H composition of the produced particles was very close to theoretically expected values. The thermal environment, atomization conditions, and residence times the particles experienced in the reactor were explored using numerical techniques; residence times in the order of 4-10 s were estimated.