A novel macromolecular surface modifier, a polypropylene-graft-poly(butyl methylacrylate) copolymer, was synthesized through the coupling of polypropylene containing maleic anhydride with monohydroxyl-terminated poly(butyl methylacrylate). The effects of the raw ratio, reaction temperature, and molecular weight of the branches on the graft reaction were studied. The graft copolymers were characterized with IR, H-1-NMR, thermogravimetry, and differential scanning calorimetry. The results of attenuated total reflection/Fourier transform infrared and contact-angle measurements indicated that polypropylenegraft-poly(butyl methylacrylate) could diffuse preferably onto the surface and be used as a surface modifier for polypropylene. (c) 2006 Wiley Periodicals, Inc.