The influence of adhesion promoters on elastic and strength properties and structure of elastomeric compositions

The effect of new promoters on the adhesion of elastic and strength properties unfilled elastomeric compositions based on synthetic isoprene rubber SKI-3 and also on the structure of their vulcanizates are investigated. Synthesized adhesion promoters constitute silica fillers modified with cobalt, nickel, and a combination of cobalt and nickel. They contain on the surface a reduced number (compared with industrial stearate, cobalt) ions of metals of variable valence. Tests are carried out to determine the dependency of changes of the tensile strength, the elongation at break and the density of the crosslinking of rubbers on dosages of the investigated adhesion promoters and amounts of metal ions on their surface. The effect of type and dosage of the synthesized promoters of adhesion of rubber to steel brassedcord on heat aging resistance of elastomeric compositions are established. It is established that the vulcanizates containing synthesized adhesion promoters have greater high temperatures resistance as compared with the rubber materials containing industrial cobalt stearate. Increasing dosages of modified silica acid fillers in elastomeric compositions, quantity of metals on their surface leads to the decrease of the resistance of vulcanizates to heat ageing. While Nickel ions have less oxidation effect on rubber, compared to cobalt ions that may be due to their lesser activity It is determined that the introduction of adhesion promoters leads to the formation of additional cross-linking. It is revealed that use the mineral promoters in the elastomeric compositions affects less the density of cross-linkage of rubber after heat aging as compared with the cobalt stearate. When administered in an elastomeric composition the silica modified nickel, increasing the crosslinking density of rubber upon exposure to elevated temperatures was observed.