Hydrolytic degradation of poly[(4,4′-oxydiphenylene)pyromellitic amido acid] in concentrated sulphuric acid and in dimethylformamide via hydrodynamic investigations

Translational diffusion and viscosity measurements were performed for poly[(4,4′-oxydiphenylene)pyromellitic amido acid] in DMF, LiCl/DMF, and 96% H₂SO₄ solutions to characterise the rate of the polymer degradation in 96% H₂SO₄ in comparison with its relative stability in organic solutions. The hydrodynamic data were obtained in different stages of hydrolytic polymer degradation at various temperatures from 20 to 80 °C. The mechanism of the degradation is discussed as well as the possibility of molecular investigations of the polymer under conditions of quasi-stable solution.