Polyolefin graft copolymers derived from linear copolymers of alpha-olefins and divinylbenzene having narrow molecular weight and composition distributions and process for preparing same

A processes for preparing a graft copolymer (II) having the structural formula

• in which:
• R is a C1 to C10 linear or branched alkyl group or a C6 to C10 substituted or unsubstituted aromatic group;
• G and G′, independently, are selected from —H[, —OH, epoxy, —NH2, —COOH, anhydride, —Cl, —Br, —M, —COOM (wherein M=metal)] and a polymer chain having the molecular weight of at least about 500;
• x is ≧0;
• y is ≧0;
• m is ≧0;
• n is at least 0.05%, with the proviso that at least one of G and G′ comprises a polymer chain;
• the combined alpha-olefin mole % (x+y) is from about 50 to 99.9%;
• the sum of x, y, m and n is 100%;
• and the backbone polymer chain has a number average molecular weight (Mn) of at least about 1,000;
• which comprises:
• contacting under polymerization reaction conditions a monomer capable of undergoing polymerization in the presence of a transition metal coordination catalyst with (a) a transition metal coordination catalyst, (b) an activating co-catalyst, and (c) a divinylbenzene comonomer unit-containing linear polyolefin copolymer (I) having the formula
• in which:
• R is a C1 to C10 linear or branched alkyl group or a C6 to C10 substituted or unsubstituted aromatic group;
• x is ≧0;
• y is ≧0;
• the combined alpha-olefin mole % (x+y) is from about 50 to 99.9%;
• and the sum of x, y, and z is 100%;
• and in which the backbone polymer chain has a number average molecular weight (Mn) of at least about 1,000, a ratio of weight average molecular weight (Mw) to number average molecular weight (Mw/Mn) less than about 4, a linear molecular structure, and a narrow composition distribution with the incorporated divinylbenzene units being distributed homogeneously along the backbone polymer chains.