Process for the polymerization of epoxides

A process for the polymerization of epoxides in the presence of a (1) double metal salt cyanide-complex catalyst of the general formula:

• M.sup.1.sub.a [M.sup.2 (CN).sub.b (A).sub.c ].sub.d.wM.sup.3 D.sub.e.xH.sub.2 O.yL.zH.sub.n E.sub.m
• wherein M.sup.1 represents at least one of Zn(II), Fe(II), Co(II), Ni(II), Mn(II), Cu(II), Sn(II) or Pb(II);
• M.sup.2 represents at least one of Fe(II), Fe(III), Co(III), Cr(III), Mn(II), Mn(III), Ir(III), Rh(III), Ru(II), V(IV) or V(V);
• M.sup.3 represents M.sup.1 or M.sup.2 ;
• A, D and E each represent an anion which may be the same or different;
• L represents an alcohol, aldehyde, ketone, ether, ester, amide, nitrile or sulfide or mixtures thereof;
• a and d are numbers to satisfy the valency state of M.sup.1 and M.sup.2 in the double metal cyanide part of the general formula;
• b and c are integers (b>c) which together with a and d provide the electroneutrality of the double metal cyanide part of the general formula;
• e is an integer satisfying the valency state of M.sup.3 ;
• n and m are integers satisfying the electroneutrality of HE and
• w is a number between 0.1 and 4;
• x is a number up to 20;
• y is a number between 0.1 and 6;
• and
• z is a number up to 5, and
• (2) at least (a) one or more salts composed of at least bivalent metal ions and metal-free anions, having a solubility in water of at least 1 g/100 ml at 25.degree. C., and/or (b) one or more non-metal containing acids of which a 0.1N solution in water at 25.degree. C. has a pH not exceeding 3.