Method for making polyolefin graft polymers having improved adhesion properties

A process for making polyolefin graft polymers having improved adhesion properties comprising the steps of:

• a) contacting at least one polyolefin in a first solvent with a first phenolic ester monomeric compound having the structure as shown in Formula (I):
• wherein R=an alkyl group having from 1 to 20 carbon atoms, or phenyl and a second monomeric compound selected from the group consisting of styrene, diene monomers, acrylate monomers, and methacrylate monomers, to form a reaction mixture;
• b) contacting the reaction mixture of step (a) with a radical initiator selected from the group consisting of benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, α,α′-bis(t-butylperoxy) diisopropylbenzene, di-t-amyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3,1,1-di-(t-butylperoxy)-3,3,5-trimethyl-cyclohexane, n-butyl 4,4-bis(t-butylperoxy)valerate, and ethyl 3,3-di-(t-amyl peroxy)butyrate;
• c) heating the mixture of step (b) from about 60° C. to about 180° C. for a time sufficient to permit polymerization and the formation of a polyolefin graft polymer comprising a phenolic ester;
• d) cooling the mixture of step (c) to a temperature of less than about 70° C.;
• e) precipitating the mixture of step (d) in a second solvent;
• f) separating the first solvent and the second solvents from the precipitated mixture of step (e);
• and
• g) deacylating the phenolic ester comprised within the polyolefin graft polymer.