The Chemistry and Technology of Rubber-Bound and Related Novel Antioxidants

Abstract

Abstract The discovery that C-nitrosoanilines react with olefins to give p-phenylenediamines has made possible the synthesis of powerful antioxidants from a wide range of naturally occurring and synthetic unsaturated compounds. Simple alkenes, vegetable oils, and factices may be converted to antidegradants whose behavior parallels that of commercially available materials. The reaction of 4-nitrosoanilines or 4-nitrosophenols with natural and synthetic rubber or latices gives rubber-bound antioxidants which are completely resistant to extraction by water or organic solvents. No major modification of technological processing or fabrication techniques is necessary, and the reaction takes place conveniently during vulcanization. Attachment of the protective group to the rubber molecule does not affect its antioxidant activity, but reduces its effectiveness when migration to the surface is required, e.g., in protection against ozone. Although faster at elevated temperatures, the nitroso-olefin reaction will occur at room temperature, and this allows the preparation of chemically modified raw rubbers by carrying out the reaction in latex before coagulation and drying.