The kinetics involved in the thermal degradation of an aryl azo dye-containing polynorbornene was investigated by using isothermal DSC data. The activation energy of the degradation was found to be temperature dependent with two different values of 140 +/- 5 and 21 +/-2 kJ mol(-1), and the Avrami exponent was observed to increase from 2 to 4 in the temperature range 573-608K. The degradation mechanism follows the Avrami-Erofeev mechanism for solid state reaction models and it changes from A2 toward A4 for the same temperature range. (C) 2011 Elsevier B.V. All rights reserved.