Incorporation of Antioxidant Groups into Polydienes. I. Via Chain Transfer Reactions of Symmetrical Dithiodiphenols

A number of substituted symmetrical dithiodiphenols and related monothio-and trithiodiphenols were prepared and characterized. Some of these dithiodiphenols showed chain transfer activity either in bulk styrene or in emulsion diene polymerizations. The fact that phenolic sulfide units were incorporated into polyisoprene and polybutadiene by use of one of these compounds, 2,2′-dithiobis(6-t-butyl-p-cresol), as chain transfer agent was confirmed by ultraviolet analysis. It was demonstrated that selfresistance to oxidation was incorporated into various diene homo- or copolymers, to varying degree, by use of some of these dithiodiphenols as chain transfer agents, on the basis of oxygen absorption tests on preextracted polymers.