Modification of emulsion polymerization by multiple addition of modifier

Model equations were used to determine approximately the optimum conditionneeded to obtain the lowest molecular weight, P̄_v, with a fixed molar amount of modifier by the addition in three portions of modifiers with different regulating indexes. Simulated calculations were also conducted to determine the effect two- and three-portion additions of a modifier had on the P̄_v/P̄_n ratio. The simulated calculations served as guides for two-, three-, and manyfold incremental modifier addition experiments. The calculations and experiments establish the need for matching the portioning of the modifier to the regulating index in order to obtain efficient use of the modifier.