Patent ID: 7612147

Claim:
A process for synthesizing a dendrimer of a rubbery polymer comprising: (a) reacting a lithium terminated rubbery polymer with a halogenated silicon containing compound to produce a polymer which is terminated with halogenated silicon moieties, wherein the molar ratio of the lithium terminated rubbery polymer to halogen atoms in the halogenated silicon containing compound is within the range of 2:n to (n−1):n, wherein n represents the number of halogen atoms that are bonded directly to silicon atoms in the halogenated silicon containing compound, wherein the halogenated silicon containing compound is of the structural formula: wherein X represents a halogen atom, wherein Z 1 groups can be the same or different and are selected from alkyl groups that contain from 1 to 8 carbon atoms and wherein x represents an integer from 1 to 20; (b) reacting the polymer which is terminated with halogenated silicon moieties with a molar excess of tertiary butyl alcohol to produce a polymer which is terminated with hydroxy silyl moieties; and (c) allowing the polymer which is terminated with the hydroxy silyl moieties to couple under conditions sufficient to produce a dendrimer containing siloxane linkages, wherein the polymer which is terminated with the hydroxy silyl moieties is coupled at a temperature which is within the range of 0° C. to 150° C.