Alkaline hydrolysis of polyacrylonitrile, 1. Structure of the reaction products

The alkaline hydrolysis of a polyacrylonitrile suspension was carried out in a water/ethanol mixture at 75°C. The product structure was studied by means of solid state 13C NMR spectroscopy. The hydrolyzed samples contain up to 20% of amidines, which are formed in the nearest neighborhood of the COONa groups. Amidines are relatively stable under the given reaction conditions up to almost complete conversion of the nitrile groups, then being hydrolyzed gradually into amides. After complete hydrolysis of the amidines, the resulting poly[(acryl amide)-co-(sodium acrylate)] exhibits a Bernoulli triad distribution of the comonomer units. The data obtained might be useful in elucidating the reaction mechanism.