DSC study of antioxidant activity of selected p-phenylenediamines in styrene-butadiene rubber

Abstract

The antioxidant activity of selected N,N′-substituted p-phenylenediamines (PPDs) in styrene-butadiene rubber (SBR) has been studied by differential scanning calorimetry under non-isothermal conditions. The kinetic parameters describing temperature dependence of induction period have been obtained. Protection factors and antioxidant effectiveness have been calculated to characterize the stabilizing effect of the antioxidants under study. It is shown that all antioxidants under study exhibit stabilizing effect on SBR. The obtained values were used to compare the stabilizing effect of the same antioxidants in polyisoprene (PI) rubber. The order of stability for SBR matrix samples differs from that for PI samples. It is shown that the stabilization effect of the antioxidant depends much on the polymer matrix.