A natural rubber latex, an acrylonitrile-butadiene rubber latex, and their 50 : 50 blends were exposed to an electron beam in air. A polyfunctional monomer, ethoxylated pentaerythritol tetraacrylate, was used as a crosslinking promoter. Cast films from the irradiated systems were characterized for their gel contents, swelling properties, and tensile strength. An increase in the radiation dose from 0 to 500 kGy resulted in increased crosslinking, as measured by an increase in the gel content and better swelling resistance. The effect of the polyfunctional monomer, ethoxylated pentaerythritol tetraacrylate, as a crosslinking promoter was studied with infrared spectroscopy. (c) 2006 Wiley Periodicals, Inc.