The process of thermal degradation of poly(vinyl chloride)/poly(methyl methacrylate-butadiene-styrene) (PVC/MBS) blends was
investigated by means of isothermal thermogravimetry in nitrogen. The total mass loss was determined after 120 min. The kinetic
parameters of the degradation process were determined by applying two kinetic models: the model which assumes autocatalytic
degradation (Prout-Tompkins) and the model of two-dimensional diffusion. It was established that the thermal degradation at
lower degrees of conversion (α<0.20) was well described by the former model, but the latter model was applicable at higher
degrees of conversion. The thermal stability of blends at a certain temperature of isothermal degradation depends on the blend
composition and the shell/core ratio in MBS, and on the adhesion in the boundary layer in PVC/MBS blends.
The PVC/ABS blends were degradated by means of isothermal thermogravimetry at temperatures at 210...240°C in nitrogen. Applying
the stationary point method to the data obtained from thermogravimetric curves, apparent activation energy, preexponential
factor and compensation parameter for each blend were calculated. The constancy of compensation parameters points to an unchanged
mechanism of poly (vinyl-chloride) (PVC) thermal degradation in the presence of acrylonitrile butadiene-styrene (ABS). Upon
increasing the fraction of ABS in the blend up to 50% only the kinetics of the process is changed.
The thermooxidative degradation of poly(vinyl chloride) (PVC), chlorinated polyethylene (CPE) and PVC/CPE blend 50/50 was
investigated by means of dynamic and isothermal thermogravimetric analysis in the flowing atmosphere of air. To estimate the
thermooxidative stability of the samples the characteristics of thermogravimetric (TG) curves were used. Kinetic parameters
(the apparent activation energy E and preexponential factor Z) were calculated after isoconversional method for the first
stage of dynamic degradation where dehydrochlorination (DHCl) of PVC and/or CPE is the main degradation reaction. Despite
the chemical resemblance, the degradation mechanisms of CPE and PVC are different, as a consequence of differences in microregularity
of the corresponding polymer chains. The addition of Ca/Zn carboxylates as well as the ratio of Ca and Zn carboxylates have
considerably different influence on the investigated polymers.