Bulk polymerization process for producing polydienes
A process for preparing a polydiene, the process comprising the steps of: polymerizing conjugated diene monomer with a metallocene complex catalyst system within a polymerization mixture that includes less than 20% by weight of solvent based on the total weight of the polymerization mixture, where the metallocene complex catalyst system includes the combination or reaction product of: (a) metallocene complex, (b) an alkylating agent, and optionally (c) a non-coordinating anion.
1. A process for preparing a polydiene, the process comprising the steps of: polymerizing conjugated diene monomer with a metallocene complex catalyst system within a polymerization mixture that includes less than 20% by weight of solvent based on the total weight of the polymerization mixture, to produce a polymer chain with a reactive chain end, and introducing a functionalizing agent into the polymerization mixture to react with the reactive polymer chain end to produce a functionalized polymer, where the metallocene complex catalyst system includes the combination or reaction product of: (a) metallocene complex, (b) an alkylating agent, and optionally (c) a non-coordinating anion, and where the metallocene complex is defined by the formula I
where M is a lanthanide-series element, scandium, or yttrium, Cp is a cyclopentadienyl group or a cyclopentadienyl derivative group, Y is a hydrocarbyloxy group, a thiohydrocarbyloxy group, an amine group, a silyl group, cyclopentadienyl group, or a cyclopentadienyl derivative group, X is hydrogen atom, a halogen atom, a hydrocarbyloxy group, a thiohydrocarbyloxy group, an amine group, a silyl group, or a monovalent organic group, each L is individually a neutral Lewis base, and n is a number from 0 through 3, or where Cp and Y are joined by a divalent group.
2. The process of claim 1 , where the polymerization mixture includes less than 5% by weight of solvent based on the total weight of the polymerization mixture.
3. The process of claim 1 , where said step of polymerizing takes place within a polymerization mixture that is substantially devoid of solvent.
4. The process of claim 1 , where Y is a cyclopentadienyl group or a cyclopentadienyl derivative group.
5. The process of claim 1 , where Y is a hydrocarbyloxy group, a thiohydrocarbyloxy group, an amine group, or a silyl group.
6. The process of claim 5 , where Y is a hydrocarbyloxy group.
7. The process of claim 5 , where Y is a thiohydrocarbyloxy group.
8. The process of claim 5 , where Y is an amine group.
9. The process of claim 5 , where Y is a silyl group.
10. The process of claim 1 , where Cp and Y are joined by a divalent group.
11. The process of claim 1 , where the conjugated diene monomer is selected from the group consisting of 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene.
12. The process of claim 1 , where the alkylating agent is an organoaluminum compound.
13. The process of claim 1 , where the alkylating agent is an organomagnesium compound.
14. The process of claim 1 , where said process employs a non-coordinating anion.
15. The process of claim 1 , where the molar ratio of the alkylating agent to the metal of the metallocene complex is from about 1:1 to about 1:100.
16. The process of claim 1 , where the alkylating agent is an aluminoxane, and where the molar ratio of the aluminoxane to the metal of the metallocene complex is from about 1:1 to about 1:100.
17. The process of claim 1 , where from about 0.0005 to about 0.01 mmol of the metallocene complex is used per 100 g of the conjugated diene monomer.
18. The process of claim 1 , where said step of polymerizing achieves a monomer conversion of from about 5% to about 60%.