HYDROLYTIC THERMAL-DEGRADATION OF POLY(NAPHTHOYLENEIMIDE BENZIMIDAZOLE) IN CONCENTRATED SULFURIC-ACID

Citation
Pn. Lavrenko et Ov. Okatova, HYDROLYTIC THERMAL-DEGRADATION OF POLY(NAPHTHOYLENEIMIDE BENZIMIDAZOLE) IN CONCENTRATED SULFURIC-ACID, Journal of applied polymer science, 56(1), 1995, pp. 97-102
Citations number
12
Categorie Soggetti
Polymer Sciences
ISSN journal
00218995
Volume
56
Issue
1
Year of publication
1995
Pages
97 - 102
Database
ISI
SICI code
0021-8995(1995)56:1<97:HTOPB>2.0.ZU;2-C
Abstract
Translational diffusion in 96% H2SO4 and intrinsic viscosity of poly(n aphthoyleneimide benzimidazole) (PNIB) have been investigated in diffe rent stages of its degradation in solution in the temperature range fr om 65 to 120 degrees C. The degradation rate constant k has been deter mined from the change in molecular weight M of degraded products with time at the fixed temperature of solution. The activation energy of th e process E was calculated from the temperature dependence of k. The d ifference in E values at low and high temperatures was found. At degra dation temperatures above 90 degrees C, the activation energy of hydro lysis was obtained as E = 133 kJ/mol, which coincides with that of aro matic polyamides in sulfuric acid. The data obtained are compared with the results of the investigations of optical properties of products o f PNIB degradation in solution and PNIB stability in the solid state. An explanation of anomalies observed during PNIB degradation at low te mperatures is suggested. (C) 1995 John Wiley and Sons, Inc.