Antioxidants and stabilizers—XXXI. A contribution to the knowledge of antioxidative properties and transformations of 2,2′-methylenebis (4-methyl-6-tert, butylphenol)

Abstract

The products of the reaction of 2,2′-methylenebis(4-methyl-6-tert, butylphenol)(1) with the tert.butoxy and tert.butylperoxy radicals, that is dimer II, trimer III and a cyclohexadienone derivative IV, were used to identify compounds formed from bisphenol I during an inhibited oxidation of tetralin (60°) and isotactic polypropylene (180°). By means of the GPC method, compounds II and III and a tetralyl analogue of compound IV were proved to be formed during the oxidation of tetralin inhibited with bisphenol I. At a high oxidation temperature of polypropylene, compounds II and III disappeared faster from the substrate in the presence of bisphenol I; however, in both the substrates under investigation their antioxidative activity was confirmed. A mixture of bisphenol I with phenols II or III does not exhibit any synergistic properties. The cyclohexadienone derivative IV has no antioxidative properties; during oxidation of polypropylene it depresses the activity of bisphenol I. At the temperature used for the oxidation of tetralin, however, its presence affected favourably the activity of bisphenol I.