EFFECT OF CHEMICAL-STRUCTURE OF SOME PYRIDAZINE DERIVATIVES AS ANTIOXIDANTS IN NATURAL-RUBBER

Pyridazine derivatives of the general formula [GRAPHICS] were prepared where R = H, CH3, OCH3 and CI. The prepared compounds were evaluated as antioxidants in natural rubber (NR) mixes by incorporating equimola r quantities of them to N-isopropyl-N-phenyl-p-phenylene diamine (IPPD ) in the standard formula of NR. The kinetic constants for the vulcani zation reaction in the presence of these antioxidants, using the rheom etric data, were calculated. It was found that the presence of electro n donating groups in the compound increases the rate of vulcanization while the presence of electron withdrawing groups decreases it. The sy nthesized compounds show good antioxidant behavior compared with the c ommercial agent (IPPD) industrially used, and the efficiency of such c ompounds depends on their chemical structure.