Effect of Chemical Structure of Some Pyridazine Derivatives as Antioxidants in Natural Rubber

Pyridazine derivatives of the general formula were prepared where R = H, CH 3 , OCH 3 and CI. The prepared compounds were evaluated as antioxidants in natural rubber (NR) mixes by incorporating equimolar quantities of them to N-isopropyl-N- phenyl-p-phenylene diamine (IPPD) in the standard formula of NR. The kinetic constants for the vulcanization reaction in the presence of these antioxidants, using the rheometric data, were calculated. It was found that the presence of electron donating groups in the compound increases the rate of vulcanization while the presence of electron withdrawing groups decreases it. The synthesized compounds show good antioxidant behavior compared with the commercial agent (IPPD) industrially used, and the efficiency of such com pounds depends on their chemical structure.