Mechanistic Study of the Effect of Adhesion-Promoter Resins on the Crystal Structure of the Copper Sulfide Adhesion Layer at the Rubber-Brass Interface

Abstract

Abstract We have previously presented the effect of adhesion-promoter resins, used in the belt compound of tires, on the mechanical properties of the rubber compounds. We have also proposed that the presence of certain adhesion-promoting resins could lead to the formation of a copper sulfide adhesion layer that might protect the residual brass from corrosion during humidity-aging conditions. Highly polished brass coupons were cured against the natural rubber compounds and the cured rubber was later removed using o-DCB (ortho-dichlorobenzene) solvent. To test our proposed theory, we studied the crystal structure of the copper sulfide adhesion layer using synchrotron source Grazing Incidence angle X-ray Diffraction (GIXRD). In this paper, we confirm our previously proposed theory that the presence of adhesion-promoting resins alters the crystal structure of the adhesion layer resulting in a durable rubber-to-brass bonding during aging conditions.