CONDUCTOMETRIC DETERMINATION OF THE END GROUP IONIZATION IN ACRYLAMIDE AND ACRYLONITRILE POLYMERS INITIATED BY CARBOXYLIC-ACIDS

The end group analysis both for polyacrylamides and polyacrylonitriles initiated by Ce(IV) malonic acid, tartaric acid and citric acid redox systems was carried out by using conductometric titration. Carboxyl e nd groups of these polymers are determined by dissolving polyacrylamid es in water, polyacrylonitriles in dimethylformamide and ethylene carb onate propylene carbonate (80/20 by weight) at 25-degrees and titratin g with aqueous sodium hydroxide, alcoholic sodium hydroxide and tetrab utylammonium hydroxide, respectively. The number average molecular wei ght results are compared with the viscometric ones. It was found that these are in good agreement with each other. In addition to the experi ments with conductometric titrations, calculations were made to find t he ionization constant of carboxylic acid end groups in acrylamide and acrylonitrile polymers. For this purpose the Ostwald dilution law was used.