The effect of acrylonitrile content on the physical properties of acrylonitrile-butadiene rubber (NBR) under electron beam induced vulcanization was studied. Diethylene glycol dimethacrylate (2G) and trimethylol propane trimethacrylate (TMPT) were used as polyfunctional monomers (containing two or more polymerizable C=C double bonds in a molecule, PFMs) to lower the irradiation dose. The effect of acrylonitrile content (AN) on physical properties was pronounced only at low doses where the crosslink densities were not too high. The crosslink density in the polymer matrix is affected by the nature of polyfunctional monomers (PFMs) and acrylonitrile content of NBR. In radiation vulcanized NBR, the crosslink density in the matrix is increased by increasing AN content with corresponding decrease in swelling. (C) 2003 Elsevier B.V. All rights reserved.