Thermogravimetric analysis of polyurethane–polysulfone blends

Thermal decomposition of blends of a poly(ester urethane) and poly(ether sulfone) with or without poly(urethane sulfone), taken as a compatibilizing agent, was studied by thermogravimetric analysis under dynamic conditions. Theoretical mass loss curves were compared with experimental ones and it was found that the blends studied possessed lower thermal stability than the pure polymers, indicating the presence of interactions in the degradation process. The shifts between the theoretical and experimental curves became smaller as the amounts of polysulfone increased, confirming the thermal stabilisation effect of this polymer. The analysis of activation energy revealed, for both binary and ternary systems, that E_CR (T_max corresponding to the main decomposition stage of polysulfone) increased as the amount of this polymer increased and also the reaction order became zero. For the polyurethane decomposition stages and blending revealed no significant changes as far as activation energy and order of reaction were concerned. © 2002 Society of Chemical Industry