Process for the anionic polymerization in the presence of cryptants

A process for the anionic polymerization or copolymerization of olefinic monomers, dienic monomers, vinyl monomers and heterocyclic monomers is described which comprises reacting at least one monomer which is an olefinic monomer, a vinyl monomer or an heterocyclic monomer with a catalyst capable of inducing anionic polymerization and an aprotic macroheterocyclic cryptant, said at least one monomer being the only medium for the reaction. The macroheterocyclic complexing agent has general formula in which: R1 is hydrogen, a hydrocarbon radical or alkoxycarbonyl, or the two R1 together can form a group of the general formula: in which A is a hydrocarbon radical, D is oxygen, sulfur, or a hydrocarbon radical, with the proviso that at leat two of the D groups are oxygen or sulfur and that if R1 is hydrogen, a hydrocarbon radical or alkoxycarbonyl, one of these two D groups is oxygen or sulfur and the other is oxygen, and n and p are integers from 1 to 3 and m is 2 or 3.