Effect of pH on the rate of emulsion polymerization of styrene initiated by potassium persulfate

The influence of pH on the emulsifier property (micellar molecular weight) of sodium dodecyl sulfate has been studied in conjunction with the effect of pH on the rate of emulsion polymerization of styrene initiated by potassium persulfate. The rate of polymerization was found to be pH dependent. The micellar weight of sodium dodecyl sulfate has been determined at various pH values. The miceller weight was found to increase with decrease in pH. On the basis of the result, a suggestion was made that the effect of pH on micellar molecular weight can account for the observed behavior of the rate of polymerization.