Effect of heat treatment on the degradation of fiber anionites

The thermal transformations of anionites synthesized on the basis of a polyacrylonitrile fiber are studied. During the heat treatment of the weakly basic anionite FIBAN A-5, the cleavage of amino groups occurs via two routes. In the case of the strongly basic anionite FIBAN A-6, dealkylation and deamination occur during heating and the dealkylation of quaternary amino groups accompanied by formation of tertiary amino groups predominates. The thermal degradation of anionites proceeds much more intensely in an aqueous medium than in an atmosphere of inert gas owing to participation of water hydroxyl in the mentioned reactions.