Rubber-bound antioxidants. I. Amine antioxidants bound to polychloroprene rubber

Abstract

This investigation is concerned with the reaction of CR type-W rubbers with amines producing polymer-bound antioxidants. Experimental data indicate that amine antioxidants are found to react with chloroprene (CR) type-W rubber with its reactive chlorine atoms. These reactions take place during high-shear mixing in a torque rheometer, or in a Winkworth mixer at higher temperature, or during the vulcanization of the elastomers at 160°C. Mixed alkyl, aryl secondary amines are shown to react only at the alkyl-substituted amino group. The concentrations of the bound antioxidants are estimated by IR spectroscopy after complete extraction. Monsanto Rheometer studies show that, in many cases, the crosslinking reaction of CR rubber, which takes place through the chlorine atom, is reduced by the presence of the antioxidants.