Critical Concentrations of Some Phenolic Antioxidants in Butyl Rubber

Abstract Induction period of oxidation of butyl rubber non-linearly increases with concentrations of antioxidants: slowly below a certain threshold or “critical” concentration, and rapidly above that concentration. Three industrial antioxidants have been studied, the most effective from those appeared to be Agidol 2: 2,2′-methylene-bis(4-methyl-6-tert.butyl-phenol) otherwise known as “Antioxidant 22–46”. The theory of the effect is considered.