A method for preparing a
functionalized polymer comprising the steps of preparing a pseudo-living
polymer by polymerizing
conjugated diene monomer with a
lanthanide-based catalyst, where said pseudo-living
polymer is characterized by having greater than about 85 percent of the
polymer in the cis
microstructure and less than about 3 percent of the polymer is in the 1,2- or 3,4-
microstructure, and reacting the pseudo-living polymer with at least one functionalizing agent defined by the formula (I) or (II) where Z is a
substituent that will react or interact with organic or inorganic fillers; R1 is a
single bond or a
divalent organic group; R2 is a monovalent
organic group or a
divalent organic group that forms a cyclic organic group with R13 or R14; R3 is a
single bond, a
divalent organic group, or a trivalent organic group that forms a cyclic organic group with R4 or R5; R13 is a
single bond, a divalent organic group, or a trivalent organic group that forms a cyclic organic group with R2 or R14; R4 is a monovalent organic group or a divalent organic group that forms a cyclic organic group with R3 or R5; R14 is a monovalent organic group or a divalent organic group that forms a cyclic organic group with R2 or R13; and R5 is a monovalent organic group or a divalent organic group that forms a cyclic organic group with R3 or R4; with the proviso that each group attached to the imino carbon is attached via a
carbon atom and R1, R2, R3, R4, R5, R13, R14 and Z are substituents that will not protonate a pseudo-living polymer.