Pyridazine Derivatives as Antioxidants in Natural Rubber

Abstract

Two pyridazine derivatives were prepared by the reaction of ani line and β-napthylamine with 3,6-dichloropyridazine. The prepared compounds were evaluated as antioxidants in natural rubber mixes. The rheometric char acteristics of the compounded rubber and the physico-mechanical properties of the vulcanizates were determined. It was found that the cure rate index, tensile strength, and modulus increase while the equilibrium swelling decreases; i.e., these compounds behave as secondary accelerators. The rubber vulcanizates were subjected to thermal oxidative ageing at 90 ° C for time periods up to seven days. It has been found that pyridazine derivatives can protect natural rubber vulcanizates against oxidative deterioration.