Three corn. ethene/n-octene copolymers (I) were blended with a corn. isotactic polypropylene (II), grafted/crosslinked with mixts. of unsatd. silanes and (PhCMe2O)(2)O under conditions of reactive extrusion at 170-190 degrees C and studied for mech. properties, thermal stability and microstructure. The composite materials consisted of a semicryst. II matrix and dispersed small particles of crosslinked I. The best mech. properties were achieved when the II/I mass ratio was 55/45.