Impact of impeller type on methyl methacrylate emulsion polymerization in a batch reactor

Abstract

The emulsion polymerization of methyl methacrylate (MMA) was carried out in a lab-scale reactor, which was equipped with a top-entry agitator, four wall baffles, a U-shaped cooling coil, and a temperature controller. Potassium per sulfate and sodium dodecyl sulfate as were used as the initiator and the surfactant, respectively. The experimental investigation demonstrated the impact of the impeller type (45° six pitched-blade turbine and Rushton impeller), number of impellers (single and double impellers), and impeller speed (100-350 rpm) on the monomer conversion, polymer particles size, molecular weight, and glass transition temperature. The results revealed that the effect of the impeller speed on the characteristics of the polymer attained using the pitched-blade turbine was more prominent than that for the Rushton turbine. It was also found that the impact of the impeller speed on the polymer characteristics was much more pronounced for the double pitched-blade turbines rather than for the double Rushton turbines. However, more uniform size distribution was achieved with the Rushton turbine. Copyright © 2014 Wiley Periodicals, Inc.