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Polymerization of propylene oxide and copolymerization of carbon disulphide and propylene oxide with xanthate salts

Aksoy, S.
Balkan, M.
Alyürük, K.
Anionic polymerization of propylene oxide (PO) using several xanthate salts was studied. Low molecular weight oily polymers with variable sulphur content were obtained by using either potassium ethyl xanthate or potassium benzyl xanthate. The highest attainable conversion of PO was limited to ca 10%. The polymerization was accompanied by formation and precipitation of a by-product salt. In the presence of CS2, an oily copolymer with about 40% sulphur was obtained from the above mixtures. In reaction systems with CS2/PO mole ratio larger than unity, all the PO in the feed could be copolymerized without precipitation of salt. Zinc isopropyl xanthate (ZnXt2) polymerized PO into a partially stereoregular high polymer. Addition of CS2 to PO and ZnXt2 solution yielded high copolymers with monomeric unit ratios (CS2/PO) of 0.06–0.15.