Copolymer networks based on 2-vinylpyridine(2VP)/styrene(STY)/divinylbenzene(DVB) and their N-oxide derivatives have been investigated by thermogravimetric analysis (TG) to evaluate their thermal stability in nitrogen atmosphere at fixed heating rate. Thermal stability was determined from TG curves to investigate the influence of 2VP content and introduction of N-oxide groups. The TG and DTG curves of unmodified copolymers clearly show two thermodegradation stages and the same kinetic pathway. The decomposition temperatures do not depend on the 2VP content and material porosity. The copolymers modified by oxidation present lower thermostability than unmodified showing that the introduction of N-oxide groups modifies their kinetic pathways. (C) 2004 Elsevier B.V. All rights reserved.