Method to reduce coupling during termination with functional end-groups
AssigneeBridgestone Corporation
InventorsJames E. Hall, James Oziomek
Life of this patent
Estimating the term…
Abstract
A novel method of preparing carboxyl-terminated polymers. A monomer is mixed with an organolithium initiator in a hydrocarbon solvent so as to anionically polymerize linear living polymer lithium chains. A trialkyl aluminum compound is also mixed so as to form polymer lithium: aluminate complexes in equilibrium with the linear living polymer lithium chains. When a cyclic anhydride terminator is mixed, the cyclic anhydride terminator preferentially reacts with the C—Li center on a living polymer lithium chain rather than with the C—Al—Li center on a polymer lithium: aluminate complex.
Claims24
A method of making polymer comprising terminating a living polymer with a cyclic anhydride, wherein said step of terminating is conducted in the presence of at least one metal alkyl compound.
A method of making linear polymers comprising functional carboxyl end-groups, the method comprising the steps of:
- (a) polymerizing a monomer in the presence of an organolithium initiator in a hydrocarbon solvent thereby forming a solution of linear living polymer lithium chains;
- (b) adding a trialkyl aluminum compound to said solution after said step of polymerizing thereby forming polymer lithium:
- aluminate complexes in equilibrium with the linear living polymer lithium chains;
- and
- (c) adding a cyclic anhydride terminator to said solution after adding said trialkyl aluminum compound.
A method of making linear conjugated diene polymers terminated with carboxyl end-groups, the method comprising:
- (a) polymerizing at least one anionic monomer in the presence of an organolithium initiator in a non-polar hydrocarbon solvent thereby forming linear living anionic polymer lithium chains in solution, said at least one anionic monomer comprising a conjugated diene monomer;
- (b) adding a trialkyl aluminum compound to said solution after said step of polymerizing;
- and
- (c) adding a cyclic anhydride terminator to said solution after adding said trialkyl aluminum compound, whereby the linear living anionic polymer lithium chains in the presence of the trialkyl aluminum compound form linear conjugated diene polymers terminated with carboxyl end-groups,
- wherein the cyclic anhydride comprises succinic anhydride or an alkyl derivative of succinic anhydride, and
- further wherein the trialkyl aluminum compound is selected from the group consisting of trialkyl aluminum compounds comprising from 1 to 10 carbon atoms per alkyl substituent.
A method of making linear polymers comprising functional carboxyl end-groups, the method comprising the steps of:
- (a) polymerizing a monomer in the presence of an organolithium initiator in a hydrocarbon solvent thereby forming a solution of linear living polymer lithium chains;
- (b) adding a trialkyl aluminum compound to said solution after said step of polymerizing thereby forming polymer lithium:
- aluminate complexes in equilibrium with the linear living polymer lithium chains;
- and
- (c) adding a cyclic anhydride terminator to said solution after adding said trialkyl aluminum compound;
- wherein said step of adding said cyclic anhydride couples less than about 50 percent of said linear living polymer lithium chains.
Dependencies are inferred from the claim text.