Hydrophilic monomer, 2-hydroxyethyl methacrylate (HEMA), and hydrophobic monomer, 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane (MPTS) were grafted on vulcanized rubber surface with simultaneous electron beam irradiation. Degree of graft polymerization was evaluated by composition ratio of imparted graft chain against trunk rubber. The composition ratio could be controlled by the monomer concentration and the irradiation dose. Grafted rubbers were evaluated by surface roughness and contact angle. Graft polymerization of HEMA decreased the contact angle from 93 to similar to 70 degrees without considerable change of the surface roughness. In the case of MPTS, the contact angle increased approximately to 108 degrees. The relationship between the contact angle of water on the modified surface and the friction at the moment of semidry was investigated as an application of the resulting rubber to wiper blade. The increase of the contact angle owing to the grafting of hydrophobic MPTS led to the decrease of Delta mu (deference between semi-dry state and dry friction). Instead, the decrease of the contact angle by grafting of hydrophilic HEMA resulted in the increase of Delta mu. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 2825-2830, 2010