A process for preparing a divinylarene dioxide including the steps of: (a) feeding one or more feed streams of the following reactants into a reactor system: (i) at least one divinylarene, (ii) at least one oxidizing agent, and (iii) at least one solvent to form a reaction mixture in the reactor system; (b) continuously reacting together the one or more feed streams of the reactants of step (a) in the reaction mixture; and (c) controlling heat removal of the reaction mixture as the reactants of step (b) react together; wherein the heat removal is sufficient to provide a residence time of the reactants in the reaction mixture of less than about 180 minutes residence time of the reactants in the reaction step (b); and an apparatus for preparing a divinylarene dioxide.