HYDROLYTIC THERMAL-DEGRADATION OF POLY(NA PHTHOYLEN IMIDOBENZIMIDAZOLE) IN CONCENTRATED SULFURIC-ACID

Translational diffusion of poly(naphthoylen imidobenzimidazole) in 96% H2SO4 was studied, and the intrinsic viscosity of the polymer in vari ous stages of thermal degradation in the solution was measured in the temperature range from 65 to 120-degrees-C. The degradation rate const ants were determined from the time variation of the MM of the polymer destruction products at fixed temperatures. The activation energy of t he process was calculated from the temperature dependence of the degra dation rate constant. The activation energy for the degradation at tem peratures exceeding 90-degrees-C is 133 kJ/mol, which is close to the activation energy for the hydrolysis of aromatic polyamides in sulfuri c acid.