The Use of Blocked Isocyanates to Increase the Adhesion of the Glue-Free Rubber – Polyester Cord

Abstract

The strength of the bond between the cord and rubber has a huge impact on the quality of reinforced structural materials. There are two methods of increasing adhesion: chemical and physical modification of the cord itself and the introduction of special additives into the rubber matrix. The authors propose to use reactive compounds - isocyanates as an additive to increase adhesion to polyester cord. In view of the complexity and toxicity of the latter, the approach of blocking isocyanate groups and the further introduction of these systems into the polymer matrix was chosen. The blocked isocyanate - 2,4 diphenylcarbamidotoluene was synthesized; the structure was identified by IR and elemental analysis. The effect of the amount of the synthesized additive on the adhesion to the polyester cord was investigated. The introduction of 2.4 diphenylcarbamidotoluene in an amount of 2.5 mass % in the standard rubber compound based on SKI-3 showed a slight increase in the adhesive strength of the rubber-polyester cord bond.