engleski

Kinetic investigation of thermooxidative degradation of poly(vinyl chloride) / acrylonitrile-butadiene-styrene blends by isothermal thermogravimetric analysis

The thermal degradation of poly(vinyl chloride) / acrylonitrile - butadiene - styrene (PVC/ABS) blends of different compositions was investigated by means of isothermal thermogravimetric analysis at temperatures of 210 - 240 Čo C in flowing atmosphere of air. The Flynn equation, the method of stationary point, and kinetic equation using Prout - Tompkins model proved to be satisfactory in description the thermooxidative degradation over 5 - 30 % conversions. The apparent activation energy E and preexponential factor Z were calculated for all compositions of PVC/ABS blends. The ratios E / lnZ are constant for pure and modified PVC and point to the unique mechanism of degradation process. Upon increasing the ratio of ABS in the PVC/ABS blend up to 50 % only the rate of the process is changed; the mechanism remains unchanged.

isothermal thermogravimetric analysis; kinetic parameters; PVC/ABS blends; thermooxidative degradation

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