Propylene-sulfur dioxide copolymer

Marvel and Weil have presented evidence to support a head-to-tail structure in the propylene sulfur dioxide copolymer [4] [see Eq. (5)]. 

Although all the olefin-sulfur dioxide resins decompose by heating well above their softening points, they can be satisfactorily molded within a fairly wide temperature range [22a]. For example, propylene-sulfur dioxide copolymers can be molded at 180°-200°C. Some properties of the molded resins are shown in Table IV [9a]. Some other examples of olefin-sulfur dioxide copolymers and their polymerization conditions are shown in Tables V-IX. 

Marvel reported that propylene and cyclohexene react with sulfiir dioxide to form alternating copolymers of olefin and sulfiir dioxide in a head-to-tail arrangement [2,4], Staudinger reported that 1,3-butadiene reacts with sulfur dioxide to form a cyclic sulfone and an amorphouse linear polysulfone [3,3a, 5]. 

Copolymers have also been prepared using mixtures of olefins with sulfur dioxide. Olefin pairs studied were butene with propylene [22-22b], butene with pentene [13], butene with isobutene [13b], butene with acrylonitrile [13,23], butene with vinyl acetate [24], butene with methacrylate esters [25], butene with acrylic esters [25], and butene with butadiene [24]. 

Vinyl acetate in the presence of other olefins reacts with sulfur dioxide to give copolymers [24]. For example 20-30% vinyl acetate in the presence of propylene or butene reacts with sulfur dioxide. 

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