Kinetics of the electrochemical degradation of polypyrrole

The kinetics of the electrochemical degradation of polypyrrole has been investigated in aqueous solutions, containing HNO3 or NaNO3. For HNO3 solution, it has been found that the first-order degradation rate constant (k) is ca: 10(-5) s(-1) within the electrode potential limits of 0.3 to 0.6 V vs. Ag/AgCl. Over 0.6 V, a steep increase of k with increasing electrode potential was found, reaching ca. 9.8 V-1 for logk. For NaNO3 solutions, the k value ranges from 2.8(.)10(-5) to 3.4(.)10(-3) s(-1) within the electrode potential limits of 0.3 to 0.9 V, and a linear slope of logk vs. E of 5.1 V-1 was found within the E limits of 0.4 to 0.9 V. (C) 2002 Elsevier Science Ltd. All rights reserved.