Process for the preparation of (co)polymers of conjugated dienes in the presence of a catalytic system comprising a vanadium bis-imine complex

Abstract

Process for the preparation of (co) polymers of conjugated dienes comprising polymerizing at least one conjugated diene in the presence of a catalytic system comprising at least one vanadium bis-imine complex having the general formula (I): wherein: m is 0 or 1; Z represents a —CRRgroup wherein Rand R, equal to or different from each other, represent a hydrogen atom; or a C-Calkyl group, preferably C-C, linear or branched; or a bivalent aromatic group optionally substituted; Rand Requal to or different from each other, represent a hydrogen atom; or they are selected from C-Calkyl groups, preferably C-C, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted; or Rand R, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 4 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C-Calkyl groups, preferably C-C, linear or branched, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; Rand R, equal to or different from each other, represent a hydrogen atom; or they are selected from C-Calkyl groups, preferably C-C, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted, aryl groups optionally substituted; or Rand R, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C-Calkyl groups, preferably C-C, linear or branched, said cycle optionally containing other heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; or Rand R, may be optionally bound each other so as to form, together with other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C-Calkyl groups, preferably C-C, linear or branched, said cycle optionally containing other heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; X, Xand X, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or they are selected from C-Calkyl groups, preferably C-C, linear or branched, —OCORgroups or —ORgroups wherein Ris selected from C-Calkyl groups, preferably C-C, linear or branched; Y is selected from ethers such as, for example, diethylether, tetrahydrofuran (THF), dimethoxyethane, preferably is tetrahydrofuran (THF); n is 0 or 1.