continuous synthesis process of diene elastomer modified with lithium amide initiator

The invention relates to a continuous method of synthesizing a modified diene elastomer comprising at least one silicon atom directly bonded to the elastomeric string, comprising: a) a polymerization step by means of n r1 to rn reactors, equipped with an internal agitation system, assumed perfectly stirred, arranged in series, n varying from 2 to 15, preferably 2 to 9, r1 reactor being supplied with an input solution comprising a solvent, one or more monomers, a anionic polymerization initiator selected from lithium amides and a polar agent, the mass conversion C1 in the first reactor is less than 70%, the total mass conversion Cn to the output of rn reactor being greater than or equal to 70%, b) a modifying step of the living diene elastomer obtained in the preceding step by means of a functionalizing agent, coupling or starring.