Poly(3-hydroxybutyrate)/organically modified montmorillonite nanocomposites (PHB/25A) were prepared by the solution-intercalation method. The non-isothermal degradation of pure PHB and PHB/25A nanocomposites was investigated in the temperature range 50-500 degrees C at four heating rates (2.5, 5, 10 and 20 degrees C min(-1)). Kinetic analysis of the non-isothermal degradation of pure PHB and PHB/25A nanocomposites was performed using isoconversional (Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Friedman) methods and the invariant kinetic parameters method. The true kinetic triplets (E, A, and f(alpha)) were determined. (C) 2008 Elsevier B.V. All rights reserved.