Hydrogenated butadiene-acrylonitrile rubber was crosslinked with (PhCMe2O)(2) and dibutyl-2,6-diisopropyl-naphthalene (1) peroxides and studied for kinetics of swelling in PhMe, loss tangent, thermal properties, microhardness, glass transition temp. and temp. of PhH crystn. in the rubber to det. the rubber network heterogeneity. Solubility parameters of the peroxides and elastomer were also detd. Use of the 1 peroxide was of advantage for mech. properties of the rubber vulcanizates.