Abstract: Zinc salts of C4-8-alkanedicarboxylic acids, obtainable by reacting C4-8-alkanedicarboxylic acids with surface-modified zinc oxide particles, said surface-modified zinc oxide particles being obtainable by treatment of zinc oxide particles with organosilanes, silazanes and/or polysiloxanes and subsequent heat treatment and/or UV irradiation of treated zinc oxide particles, and the use thereof as polymerization catalysts for the preparation of polyalkylene carbonates.

Abstract: Production of polyalkylene carbonates via polymerization of carbon dioxide with at least one epoxide of the general formula (I): where R re mutually independently H, halogen, NO2, CN, COOR? or C1-20-hydrocarbon moiety, which can have substitution, where one of the moieties R can also be OH, and where two moieties R can together form a C3-5-alkylene moiety, R? is H or C1-20-hydrocarbon moiety, which can have substitution; n a zinc salt of C4-8-alkanedicarboxylic acids as catalysts, where a carboxylic acid or an acidic ion exchanger and a non-water-miscible organic solvent which dissolves the polyalkylene carbonate are admixed with the reaction mixture obtained after the reaction, and the organic phase is washed with water, and the polyalkylene carbonate is optionally obtained from the organic phase.