New impact modifiers composed of a ground tire rubber core and acrylates and styrene copolymer shell have been obtained by using a suspension grafting polymerization. The corresponding rigid poly(vinyl chloride)/grafted ground tire rubber (RPVC/GGTR) composites with different contents of GGTR were then prepared in a Haake torque rheometer. Similar composites with raw ground tire rubber (without grafting polymerization) have also been prepared for comparison. Thermal stability, processability, mechanical properties, and surface morphology of the composites were extensively investigated by thermal gravimetric analysis (TGA), rheological measurement, tensile and impact tests, and scanning electron microscopy (SEM). The results showed that GGTR improved the processability of the RPVC/GGTR composites. The Izod impact strength of the composites could be significantly enhanced by the GGTR, while the tensile strength of the composites was almost unchanged, thus showing a large potential application in the fields of building materials such as poly(vinyl chloride) profiles. J. VINYL ADDIT. TECHNOL., 2015. © 2015 Society of Plastics Engineers