Behaviour of MAn-based polyelectrolytes in water solutions: Influence of pH and ionic strength

By heterogeneous copolymerization in benzene, maleic anhydride (MAn) copolymers differing in the ratio of hydrophilic/hydrophobic units were synthesized in order to study their behaviour in water solution. The conformational behaviour of the MAn copolymers arising from variations of pH and ionic strength was followed by viscometric measurements. The MAn copolymers in water solution exhibit relatively sophisticated conformational changes partially resulting from the different character of carboxyl groups generated during hydrolysis of anhydride rings. It has been found that the conformational changes not only depend on anhydride units themselves but are also considerably affected by the polarity of a monomer unit located in the neighbourhood of an anhydride residue.