The effect of solvents on the emulsion polymerization of vinyl monomers

The rate of emulsion polymerization of vinyl compounds such as styrene, methyl methacrylate, acrylonitrile and vinyl acetate may be modified by the use of solvents. The presence of small concentrations of solvents causes an acceleration of the rate of emulsion polymerization. Increasing the concentration of the good solvent for the polymer results in a gradual decrease in the polymerization rates, but poor solvents accelerate the rate of polymerization, even in relatively large concentrations. High-viscosity-poor solvents also produce an increase in the rate due to an inductive Trommsdorff effect. Very large concentrations of either good or poor solvents decrease the polymerization rate due to a dilution effect.