Method for preparing a diene elastomer, such as a polybutadiene

The invention relates to preparing the group consisting of method. The invention is suitable for especially of greater than or equal to 40 and Nepal viscosity ML (1+4,) is less than the cold area of 2.1 of disperse index and reducing with high Syn-form-1,4 generating layer, polybutadiene and polyisoprene. Method of the invention comprises the catalytic system and at least one conjugated diene monomer reaction, the catalytic system based on at least: A conjugated dienes, organic phosphate salt of one or more rare-earth metal salt, wherein is at least one unsaturated fatty group or cyclic hydrocarbon of the base in the solvent, the general formula of the alkylating agent according AlR3 or HAlR2 aluminium alkyl, comprising and except aluminium alkyl sesquialter halide is halogenated aluminium alkyl group donor is. A method for treating the monomer of polymerization and at least one with the catalytic system alkylating agent same or different general formula AlR3 or HAlR2 the bias contact of aluminium alkyl compound (offset contact), the medium-based the quality of the polymerization conditions and/or treatment of the elastomer is obtained, preferably amount is.