HYDRODYNAMIC BEHAVIOR OF AN AROMATIC POLY AMIDE CONTAINING SULFO GROUPS IN CONCENTRATED SULFURIC-ACID

The translational diffusion of an isophthalic-acid-derived aromatic po lyamide (PA) containing sulfo groups was studied in water, 7% aqueous H2SO4, and concentrated sulfuric acid with NaCl additives. In 96% H2SO 4 + 1 M NaCl, the intrinsic viscosity [eta] and diffusion coefficient are related to the molecular mass M of PA by the formulas [eta] = M(2) (48 + 0.9M(1/2))(-3), D = 10(-6)M(-1)(90 + 1.7M(1/2)), which are vali d for M values ranging from 3 x 10(3) to 35 x 10(3). The parameters of PA conformation are evaluated. The features of the hydrodynamic behav ior of PA in aqueous H2SO4 solutions of various concentrations and in 96% sulfuric acid with the addition of various salts are discussed.