Polypropylene copolymer (PP-cp) has a large number of applications and is preferred over the homopolymer due to its higher impact strength. These impact properties can be further improved by blending with polyolefinic elastomer (POE). Blends were prepared by using commercially available POE (Engage(R) EG 8150, Dupont-Dow Elastomers), by varying POE content up to 25%. The effect of processing conditions on the properties of the blends was studied. Although impact strength increased, flexural modulus decreased. Dicumyl peroxide caused chain scission of PP-cp rather than crosslinking of POE. The results seem to indicate that there may be optimum concentration of POE around 10% for the polymers used in the present work. The grade of PP-cp used in this work contained about 10-11% ethylene content (rubber phase around 17-18%). These results match with general observations that brittle-tough transition for PP occurs when total elastomer content is about 20-25%. (C) 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1480-1484, 2000.