Patent ID: 8703873

Claim:
A method of making a multifunctional graft polymer comprising: (a) reacting a polymer comprising a backbone, the polymer having graftable sites and a weight average molecular weight in the range of from about 10,000 to about 500,000, and a coupling agent selected from the group consisting of acylating agents and epoxides and having at least two component coupling sites, at least one of which is a site of olefinic unsaturation, in the presence of an initiator to form a graft reaction product having coupling groups on the backbone of the polymer available for reaction; (b) reacting the graft reaction product formed in step (a) with an ethylenically unsaturated monomer having from 2 to about 50 carbon atoms and containing at least one of nitrogen and oxygen in the presence of an initiator to form a graft reaction product of the ethylenically unsaturated monomer and the polymer; (c) reacting the graft product formed in step (b) with an amine capable of reacting with the coupling groups on the backbone of the polymer to form a reaction product of the amine and coupling groups on the polymer backbone; and (d) reacting an organo-metallic compound with the product of step (c) to form the multifunctional graft polymer.