Pyrolysis of maleic anhydride-treated polybutadiene (PB) was studied using pyrolysis-gas chromatography (Py-GC) at 400-800 degrees C. The major pyrolysis products were butadiene, cyclopentene, cyclohexadiene, 1,4-cycloheptadiene, 4-vinylcyclohexene, 2-(cyclopent-3-enyl)ethenone and 5-cycloheptadiene-1-one. The 2-(cyclopent-3-enyl)ethenone and 2,5-cycloheptadiene-1-one were formed by primary dissociation of maleic anhydride moiety. Relative abundances of cyclopentene, cyclohexene and 1,4-cycloheptadiene increased with increase of the pyrolysis temperature, while those of 4-vinylcyclohexene, 2-(cyclopent-3-enyl)ethenone and 5-cycloheptadiene-1-one decreased. Levels of the relative abundance changes of the pyrolysis products with the pyrolysis temperature were larger for the maleic anhydride-treated PB than for the untreated one. Activation energies to form the pyrolysis products were calculated and compared. (c) 2006 Elsevier B.V. All rights reserved.