Behaviour of Thermal Degradation of Some Poly (4-amino-2,6-pyrimidinodithiocarbonate) Metal Complexes

The thermal decomposition behaviour of the Fe(II), Co(II) and Ni(II) complexes of poly[4-amino-2,6-pyrimidinodithiocarbamate] has been investigated by thermogravimetric analysis (TGA) at a heating rate of 10°C min-1 under nitrogen. The Coats-Redfern integral method is used to evaluate the kinetic parameters for the successive steps in the decomposition sequence observed in the TGA curves. The processes of thermal decomposition taking place in the three complexes are studied comparatively as the TGA and DTA curves indicate the difference in the thermal decomposition behaviour. The thermal stabilities for the release of the fragments at the successive steps in the sequential decomposition of these complexes are discussed in terms of electronegativity and ionic size effects. The difference in thermal stability and the inconsistent variation in the kinetic parameters of these complexes are considered.