The role of oxide structure on copper wire to the rubber adhesion

Most metals have an oxide layer on the surface. However, the structure of t he oxide varies with the matrix composition, and depends upon the environme ntal conditions. A bronze coating, nominal composition of 98.5% Cu and bala nce of Sn, is applied to steel wire for reinforcing pneumatic tire beads an d to provide adhesion to rubber. This work studied the influence of copper oxides on the bronze coating on adhesion during vulcanization. To emphasize the oxide structures, electrolytic tough pitch (ETP) copper wire was used instead of the traditional bronze-coated tire bead wire. Experimental results confirmed the hypothesis that cuprous oxide (Cu2O) cou ld significantly improve bonding between copper wire and rubber, and demons trated that the interaction between rubber and oxide layer on wire is an el ectrochemical reaction. (C) 2000 Elsevier Science B.V. All rights reserved.