Thermal behaviour of polyurethane interaction products with cobalt ions

Abstract

This study deals with the effects of a transition metal ion, cobalt on the thermal behaviour of polyurethane materials. A series of interaction products with cobalt ions of a segmented polyesterurethane prepared from 4,4′-diphenylmethane diisocyanate, poly-(ethylene-co-diethylene adipate)diol and ethylene glycol were synthesized and their thermal degradation investigated in comparison to that of the original polyurethane by thermogravimetric analysis. The activation energy of the thermal degradation was estimated from the thermogravimetric data by the Coats–Redfern and Levi–Reich methods. It was found that modification of the polyurethane with cobalt ions induces changes in its decomposition mechanism. All the steps of polyurethane decomposition are affected by the presence of cobalt ions and the modifications in mass loss, maximum rate of mass loss and corresponding temperature are specific for every step. It was shown that cobalt ions generally favour the degradation, having a significant catalytic effect on its final stage. In general, the favourable influence of cobalt ions on the processes involved in polyurethane decomposition tends to become more pronounced as their amount increases.