Characterization of the Steel Tire Cord - Rubber Interface

Abstract

Brass-coated steel cords are extensively used as reinforcement material in radial tires, high-pressure hydraulic hoses and heavy duty conveyor belts. Bonding between rubber and steel cord is obtained via the formation of an adhesion interface layer during the curing process. The adhesion build-up mechanism involves the chemical reaction of sulfurating species contained in the rubber skim compound and copper of the brass coating, forming a CuxS layer at the rubber-brass interface. Advances in mechanistic investigations are presented, using analytical techniques such as X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), atomic force microscopy (AFM) and optical microscopy (OM). XPS and AES provide chemical in-depth information, whereas OM and AFM highlight the morphology of the resulting interfacial layers. These investigations improve the understanding of the adhesion mechanism, both for adhesion buildup and for bond degradation.

On characterizing microscopically the adhesion interphase for the adhesion between metal and rubber compound part I. Effect of hexamethoxymethylmelamine in rubber compound

“…Brass-plated steel cords inserted in the belt and carcass of tires have long been used as a reinforcing material to provide sufficient mechanical strength and stability to endure cars themselves and their loads [1]. Brass plating on the surface of steel cords reacts with sulfur in the rubber compound during the curing process of tire manufacturing, forming an adhesion interphase between the rubber compound and the steel cord [1][2][3][4][5][6][7][8][9]. Copper and zinc also react with oxygen and water in the rubber, forming oxides and hydroxides of copper and zinc.…”

The combination of surface enhanced Raman spectroscopy and an ionic liquid as a model system to study the adhesion interface between sulfur and brass

“…Steel cords are extensively used to reinforce rubber compounds and to provide strength in radial tyres, high pressure hydraulic hoses and heavy duty conveyor belts . To promote the adhesion of steel wire to rubber, the steel substrates are often plated with brass .…”

“…Steel cords are extensively used to reinforce rubber compounds and to provide strength in radial tyres, high pressure hydraulic hoses and heavy duty conveyor belts. [1] To promote the adhesion of steel wire to rubber, the steel substrates are often plated with brass. [2][3][4][5] The adhesion build-up mechanism involves the chemical reaction of sulfuring species in the rubber with the copper of the brass coating leading to a Cu x S layer at the rubber-brass interface.…”

“…[5,6] Analytical characterization of the steel cord-rubber interface has been essential to come to better understanding of the nature of the adhesion mechanism. Various ex-situ techniques (SEM/EDX, XPS, AES, TOF-SIMS, TEM, AFM) have been used to study the interface [1][2][3] A currently used technique to study adhesion and corrosion mechanisms at the interface is electrochemical impedance spectroscopy (EIS). [6] The goal of this study is to find an additional analytical/chemical supporting tool during these electrochemical measurements.…”

Investigation of the effects of adhesion promoters on the adhesion properties of rubber/steel cord by a new testing technique

“…Crosslink density measured by MR‐CDS also increased as the cobalt loading increased, suggesting that cobalt decanoate had little effect on scorch safety, but improved cure rate and cure degree remarkably. Tensile strength, 100% modulus, and hardness increased by incorporating cobalt decanoate into the rubber compounds due to a significant increase in crosslink density with more single disulfide bonds . Additionally, it is worth noting that at a cobalt loading of 2.0 phr a maximum in tear strength was achieved.…”