Radiation-induced cryogenic copolymerization of some monomers with sulfur dioxide

A comparative study was performed on the radiation postpolymerization of a number of dienes and alpha -olefins with sulfur dioxide occurring both on h eating of the samples radiolyzed at 77 K and spontaneously by mutual dissol ution. The cryopolymerization of sulfur dioxide with butadiene was studied in most detail. It was found that, unlike the case of the isoprene-SO2 syst em, a polycrystalline phase with the eutectic that corresponded to the equi molar composition was formed on rapidly freezing over the entire range of i nitial ratios between the butadiene and SO2 comonomers. It was suggested th at the 1 : 1 donor-acceptor complex takes part in the postpolymerization pr ocess, and the monomers enter the resulting copolymer in a near-equimolar r atio. The copolymer obtained was found to behave as a crosslinked system. I t is likely that a three-dimensional network resulted from the opening of C =C bonds in butadiene.