1.1 This test method covers the Wiijs procedure for the determination of unsaturation (iodine value) in hydrogenated nitrile rubbers.

1.2 This test method is applicable only to those hydrogenated nitrile rubbers derived from copolymers of acrylonitrile and butadiene.

1.3 Iodine values are reported in centigrams of iodine per gram of HNBR [cg(I₂)/g]. Higher iodine values indicate higher levels of unsaturation.

1.4 This test method is appropriate for calculating the percent residual unsaturation of hydrogenated nitrile rubber if the iodine value of the base polymer before hydrogenation has been determined.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.