Post-polymerization of methyl methacrylate after electroinitiation at the anode

Abstract

It has been found that aqueous solutions of methyl methacrylate (MMA) containing sodium acetate when electrolyzed between platinum electrodes in an almost closed large test tube go on yielding the polymer for a long time, extending over a couple of days even after the current is switched off. MMA (ca. 1% v/v) and sodium acetate (0.2–0.6N) give good yield of polymer. In a typical experiment, when a 1% MMA solution in 0.3N sodium acetate is electrolyzed for about 2 hr with a current of about 100 mA, a yield in the range of 5% is obtained; however, if the system is left undisturbed after switching off the current, the almost clear solution grows turbid due to postpolymerization and after 24 hr gives a polymer yield of about 60–70%. The intrinsic viscosity of the polymer samples in benzene ranges from 1.6 to 3.7 Long-lived free radicals not visible to the naked eye are presumably formed whose nature is yet to be elucidated.