Flow synthesis of monodisperse micron-sized polymer particles by heterogeneous polymerization using a water-in-oil slug flow with a non-ionic surfactant

Flow synthesis of poly(methyl methacrylate) particles was performed by heterogeneous polymerization of methyl methacrylate using a water-in-oil (W/O) slug flow with or without a non-ionic surfactant in the continuous organic phase. It was found that undesired phenomena in this polymerization system, clogging of the channel and broadening particle size distribution, can occur when growing polymer particles adsorb to the W/O interface during polymerization, and that the addition of non-ionic surfactant to the continuous organic phase prevents the particles from adsorption to the W/O interface and gives monodisperse polymer particles. In addition, it was shown that as the initiator concentration increases, the particle diameter becomes larger, resulting in monodisperse micron-sized polymer particles with 100% monomer conversion at a 120-min reaction time. These results indicated that the heterogeneous polymerization process using a W/O slug flow can be a promising way to continuously prepare monodisperse polymer particles with micron sizes in a short reaction time.