Compatibilization of the blends of polydimethyl siloxane (PDMS) rubber and low-density polyethylene (LDPE) was achieved through reactive processing. during extrusion in a Monsanto Processability Tester (MPT). The chemorheological characteristics of 50: 50 LDPE : PDMS blends with varying proportions (0-8 wt %) of ethylene comethyl acrylate (EMA) were investigated at three different temperatures (170, 190, and 210degreesC) and four different shear rates (61.3, 122.6, 306.6, and 613.1 s(-1)). It was found that EMA reacts with vinyl groups of PDMS rubber at a temperature of 190degreesC during extrusion through the capillary of MPT, forming EMA-grafted-PDMS rubber (EMA-g-PDMS), which acts as the compatibilizer for the blend systems. The results. are based on IR spectroscopy, melt rheology, and phase morphology of the blends. (C) 2003 Wiley Periodicals, Inc.