Study of the polymers obtained by electroreduction of methacrylonitrile

In this work, we studied the electrochemical formation of polymethacrylonitrile by cathodic polarization in an anhydrous organic medium, at two different working potentials either side of the potential of the high concentration reduction pre-peak. In both cases, the polymer formed in solution and the so-called grafted polymer were obtained. A detailed analysis has been performed by infrared reflection absorption spectroscopy for the polymer chemisorbed on the cathode surface, and by size exclusion chromatography, infrared and 13C nuclear magnetic resonance for the polymer obtained in solution. These analyses reveal essentially no difference, in terms of products of reaction, between the synthesis carried out at the two working potentials, and suggest that the grafting reaction is probably disconnected from the occurrence of the pre-peak. On the contrary, it is proposed that this peculiar peak is due to the dynamic formation of the polymer in solution, and that this hides all effects possibly stemming from surface chemical reactions.