The presented derivative thermogravimetric and mass spectral data, obtained simultaneously for the pyrolysis of three different tyre rubbers, corroborate the assumption that the devolatilisation of a tyre rubber proceeds via two consecutive zones of weight loss and that these zones are characterised by different products and thus different reactions. The spectral data of the depolymerisation products moreover confirm that depolymerisation occurs exclusively (in case of polyisoprene rubber) or predominantly (in case of the polybutadiene rubbers) during primary devolatilisation. (C) 2015 Elsevier B.V. All rights reserved.