| Economics drive the industry to seek new processes and process improvements. Such improvements and innovations result from experience and research. This work strives to develop a process innovation by way of research in the field of emulsion polymerization.; Several research projects have attempted to use the energy from ultrasound to drive emulsion polymerization reactions or to modify the properties of polymers. While successes in modifying polymer properties are plenty, notable successes in driving polymerization reactions are scarce. Rather than develop a process driven entirely by ultrasound, this work looks to augment the conventional emulsion polymerization reaction by adding ultrasound to the reactants.; The primary objective is to increase the emulsion polymerization rate by using ultrasound. To achieve this objective, two monomers, methyl methacrylate and styrene are individually subjected to polymerization reactions using various recipes. The reaction mixture contains 10% monomer by weight, with water making up the remaining 90%. The effects of three initiators, AIBN, KPS and FeSO 4 are studied. The initiators are used in three concentrations of 0.05%, 0.0275% and 0.005% and at three temperatures 40°C, 50°C and 60°C. Conversion rates from conventional emulsion polymerization experiments are compared with results from ultrasound assisted experiments. The ultrasound is employed in two modes, continuous and pulsed mode. The experiments are based on a fractional factorial design.; From the analysis of the results, use of ultrasound results in an increase in conversion rate ranging from 0% to 250%. For a processing time of 2 hours, there is also an ultrasound induced increase in the total monomer conversion ranging from 0% to 150%. The highest increases are achieved when the initiator concentration and temperature are lowest. Also, the effects are most pronounced for the oil soluble initiator AIBN, and barely noticeable for the water soluble KPS. In the case of FeSO4, the overall conversion and rates are very low.; It is noted that use of ultrasound results in a slight decrease in molecular weight and increase in polydispersity of the polymer. Increases are also noted in particle size and size distributions. There was no discernable effect on the value of TG. |
