Thermal behaviour of some polystyrenes with pendent viologen groups

Polystyrenes with pendent diquaternary 4,4-bipyridinium groups are polystyrenes containing pendent viologen groups. They were obtained by the reaction of chloromethylated polystyrene with N-monoquaternary-4,4-bipyridinium bromides as: N-(p- H, NO2, Cl) phenacyl-4,4 -bipyridinium bromides and N-carbomethoxymethyl/ ethyl-4,4 -bipyridinium bromides (2a-e), Thermal stabilities of polystyrene with pendent viologen groups were investigated The influence of the chemical structure of pendent viologen groups on the thermal stability was performed by thermogravimetric analysis in the dynamic conditions of temperature and atmospheric air. The substituted compounds undergo a thermal degradation process that took place by a complex mechanism in three steps. These steps are disscused from both kinetic parameters and thermogravimetric characteristics points of view. The thermostability of low molar mass compounds la-e decreases in the following order. 1c > 1a > 1e > 1d > 1b and the same thermostability order was found in the case of chloromethylated polysulfone derivatives (2c > 2a > 2e > 2d > 2b).