wherein R8 is an alkyl group or an alkyl aryl group, selected from the group consisting of primary, secondary and branched chain alkyl groups, primary, secondary and branched chain alkenyl groups, and/or primary, secondary and branched chain alkyl- and alkenyl-substituted phenolic groups having from about 6 to about 20 carbon atoms, preferably from about 8 to about 18, more preferably from about 1