SYNOPSISBis (diisopropyl) thiophosphoryl disulfide (DIPDIS) can be successfully used to form a blend comprising polar carboxylated nitrile rubber (XNBR) and nonpolar NR through a chemical link between the two. It is revealed from the study that the physical properties of the vulcanizates obtained from the NR-XNBR blend could be significantly improved by the judicious selection of the NRXNBR ratio. These properties can further be improved by two-stage vulcanization as described in the procedure. The SEM study reveals that it is possible to form a coherent blend of NR and XNBR in the presence of DIPDIS. 0 1994