Kinetic study of effect of Irganox E antioxidants on thermal degradation of poly(vinyl chloride)

The effect of three Irganox E-type antioxidants (E 17, E 120, and E 201), b ased on alpha -tocopherol, on poly(vinyl chloride) thermal degradation rate at 180 degreesC has been studied. Fifteen film samples, which consisted of suspension poly(vinyl chloride), lubricant, and antioxidant, were prepared . Four samples contained a Ca/Zn stabilizer system with an epoxy co-stabili zer and Irganox E 201. Degradation in real atmosphere was followed by conti nuous potentiometry. The time of thermal stability tau and gradient of degr adation dn(HCl)/dt values were evaluated from the measured kinetic curves. Values of tau in the case of samples containing Ca/Zn stabilizer system did not overlap 90 min, their colour stability is approximately 25-30 min. Cal culations of the kinetic parameters have shown that the studied antioxidant s from the Irganox E group do not cause the polyene sequences growth termin ation.