Process for producing polydienes

A process for preparing a polydiene, the process comprising the step of:

• (i) providing a mixture of conjugated diene monomer and a solvent, where the mixture includes more than 20% by weight of solvent based on the total weight of the mixture;
• (ii) introducing a dihydrocarbyl ether directly and individually to the mixture, where the dihydrocarbyl ether is defined by the formula R—O—R, where each R is independently a hydrocarbyl group or substituted hydrocarbyl group selected from the group consisting of alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl groups, and benzyl groups;
• and
• (iii) polymerizing the conjugated diene monomer by using a lanthanide-based catalyst system, where the lanthanide-based catalyst system is formed by introducing (a) a lanthanide compound, (b) an alkylating agent, and optionally (c) a halogen-containing compound separate from the lanthanide compound or the alkylating agent, with the proviso that the catalyst system includes a labile halogen atom.

A process for preparing a polydiene, the process comprising the step of:

• (i) providing a mixture of conjugated diene monomer and a solvent, where the mixture includes more than 20% by weight of solvent based on the total weight of the mixture;
• (ii) introducing a dihydrocarbyl ether directly and individually to the mixture;
• (iii) polymerizing the conjugated diene monomer by using a lanthanide-based catalyst system;
• where the dihydrocarbyl ether is selected from the group consisting of n-butyl methyl ether, isobutyl methyl ether, sec-butyl methyl ether, t-butyl methyl ether, n-butyl ethyl ether, isobutyl ethyl ether, sec-butyl ethyl ether, t-butyl ethyl ether, t-amyl methyl ether, t-amyl ethyl ether, benzyl n-ethyl ether, benzyl n-propyl ether, benzyl isopropyl ether, benzyl n-butyl ether, benzyl isobutyl ether, benzyl t-butyl ether, and benzyl n-octyl ether.