This invention relates to a method for producing functionalised telechelic oligomers, comprising two steps. The first step relates to bringing a raw material comprising at least one high-molecular-weight polymer comprising at least two unsaturations, into contact with a solution comprising at least one metathesis catalyst and at least one functionalising agent. The second step relates to the separation of the functionalised telechelic oligomers produced by the metathesis reaction in ionic liquid medium of the first step.

The polymer of the present invention is a synthesized polyisoprene or an isoprene copolymer. The polymer has a number average molecular weight (Mn) of 1.5 million or more when measured by using gel permeation chromatography (GPC).

The polymer of the present invention is a synthesized polyisoprene or an isoprene copolymer. The polymer has a number average molecular weight (Mn) of 1.5 million or more when measured by using gel permeation chromatography (GPC).

The present invention relates to a conjugated diene-based polymer having high processability and excellent compounding properties, a preparation method thereof and a rubber composition including same, and provides a neodymium-catalyzed conjugated diene-based polymer satisfying all conditions of (a) to (c), a preparation method thereof and a rubber composition including same.