STRUCTURE AND MECHANICAL-PROPERTIES OF NITRILE RUBBERS MODIFIED WITH IODINE

Nitrile rubbers, both common and hydrogenated, revealed some kind of o rdering, as detected by WAXS. Strain induced crystallization is respon sible for the enhanced degree of crystallinity for HNBR. In the case o f NBR, another mechanism has been proposed, namely specific interactio ns between carbon-carbon double bonds from butadiene and cyano groups from acrylonitrile monomer units, leading to an EDA complex formation. Iodination reduces the degree of crystallinity of both materials; how ever, their stiffness increases as the result of modification, probabl y due to dipole-dipole interactions or hindering effects accompanying introduction of ''large'' iodine atoms into the macromolecular structu re. (C) 1998 John Wiley & Sons, Inc.