Oligo(trimethylene carbonate) and oligo(neopentyl carbonate) diols were obtained by the polymerisation of corresponding six-membered cyclic carbonates in the presence of catalysts prepared in the reaction of water with diethylzinc or triethylaluminium. Their structures were pro vm by means of MALDI TOF and NMR spectroscopic studies. The oilgocarbonate diols were reacted with 4,4' -methylenebis(phenyl isocyanate) in the presence of 1,4-butanediol as the chain extender to obtain polyurethane elastomers. The physical and mechanical properties and hydrolytic stability of novel polyurethane elastomers were compared with those of conventional materials based on polyester type soft segments.