Thermolysis of keto-RDX (K-6) and its plastic bonded explosives (PBXs) containing Kel F and Viton A was studied using various thermoanalytical techniques. The PBXs decompose at slightly lower temperatures than K-6 with higher heat release. Kinetic analysis of isothermal TG data was done by using both model fitting methods and a model free isoconversional method. Model fitting methods gave nearly same values of activation energy for all the samples. But the model free isoconversional method showed that the activation energy is dependant on extent of conversion and different values were obtained for thermolysis of K-6 and PBXs. The value of activation energy converged to a limit above alpha approximate to 0.75. This limiting value was close to the activation energy obtained by model fitting methods. Rapid thermolysis of the samples was studied using ignition delay measurements and deriving kinetic parameters out of the data. Activation energy for thermal ignition was nearly the same for all the samples. (C) 2004 Elsevier B.V. All rights reserved.