RADIATION VULCANIZATION OF HYDROGENATED ACRYLONITRILE-BUTADIENE RUBBER (HNBR)

Raw polymer and compound of hydrogenated acrylonitrile butadiene rubbe r (HNBR) were subjected to gamma-ray irradiation. Crosslinking was fou nd to be the main chemical reaction induced by irradiation; the ratio of chain scission to crosslinking as well as the dose at which gelatio n occurred were determined from gel content measurements to be 0.41 an d 3.8 Mrad, respectively. The excellent hot-air and oil-resistant prop erties should be retained because no formation of double bonds or chan ging of the nitrile groups were observed within the optimum dose range . Desired mechanical properties of the vulcanizate may be conveniently obtained by controlling the radiation dose. (C) 1994 John Wiley & Son s, Inc.