Polymer blends of carboxylated butadieneacrylonitrile copolymer (nitrile rubber) and polyamide 6 (PA6) were developed in twin screw extrusion. The rubber was cured with SP 1045 methylol phenolic resin during melt mixing in twin screw. Effect of degree of carboxylation in the rubber phase on blend properties has been assessed. Phase morphologies have been characterized using transmission electron microscopy. A compatibilizing NBR-g-NyIon 6 graft copolymer generated iu situ during melt mixing via interfacial reaction between the -COOH groups in NBR and the -NH2 end groups in nylon 6 has been effective in generating a fine and stable dispersion of the rubber within the polyamide matrix. The graft copolymer has been characterized by DMTA. (c) 2007 Wiley Periodicals, Inc.