Degradation kinetics of poly(imide-silica) hybrid films based on 4-4'-(hexafluro isopropylidene) bis(phthallic anhydride) and bis(4-aminophenyl) ether were investigated by thermogravimetric analysis TGA and DTG. The results indicated that the presence of inorganic content influence the mechanism of degradation of organic phase. Energy of activation of degradation for the hybrids with varying inorganic content was determined by the Flynn-Wall-Ozawa, pseudo first-order, van Krevelen methods. Although the values of E, calculated by using various methods are different, there is a similar change trend of E-a between those methods. (c) 2007 Wiley Periodicals, Inc.