Photopolymerizations of Methyl Methacrylate with N-Cetylpyridinium Bromide and N-Cetylpyridinium Chloride in Aqueous System

The photopolymerizations of methyl methacrylate (MMA) with N-cetylpyridinium bromide (CPB) and N-cetylpyridinium chloride (CPC) were investigated in aqueous system. With CPB alone, photopolymerization did not proceed, but by the addition of a small quantity of CCI sub 4 , it was significantly accelerated. The rate of the photopolymerization of MMA with CPB in the presence of CCI sub 4 showed a linear relationship with the square root of CPB concentration, but was little affected by the concentration of CCI sub 4 . With CPC MMA also photopolymerized in the presence of CCI sub 4 , and especially at more than a critical micelle concentration (CMC) or CPC, the time-conversion curve showed a characteristic feature of emulsion polymerization, where R sub p was proportional to the 0.75 power of the fed quantity of CPC, but almost independent of CCI sub 4 concentration. The above photopolymerizations with CPB and CPC in the presence of CCI sub 4 were, however, remarkably accelerated by the addition of KBr.