Potentiometric titration of copolymers of maleic and fumaric acids with 2-methyl-5-vinylpyridine

In previous communications [1, 2] it was shown that polyampholytes based on two unsaturated, stereo-isomeric acids (maleic and fumaric) and 2-methyl-5-vinylpyridine are substantially different in their behaviour in titration. This was associated with the different spatial configurations of the carboxyl groups in these copolymers. Another important feature of polyampholytes of this type, also associated with the use of an ethylene-1,2-dicarboxylic acid as one of the comonomers, is that the acidic component units in the copolymer will alternate with a definite number of units of the basic component. The purpose of the present work was to extend the study of the behaviour of these polyampholytes in potentiometric titration. In contrast to the earlier work attention here was directed mainly to study of the effect of change in the ratio of acidic and basic groups in the copolymers on their behaviour in titration.