Blends of poly(vinyl chloride) (PVC) and chlorinated polyethylene-chlorinating graft-hydroxy ethyl acrylate copolymer (CPE-cg-HEA) were prepared. CPE-cg-HEA, as toughening modifier, is a graft copolymer with a backbone of chlorinated polyethylene (CPE) and branched chains of poly(2-hydroxy ethyl acrylate) (PHEA). Compared with PVC/CPE, CPE-cg-HEA demonstrated better toughening effects on the blends in the tensile strength, elongation at break, and impact strength. Particularly, compared to PVC/CPE blends PVC/CPE-cg-HEA blends with 5 phr CPE-cg-HEA showed an increases in the tensile and notched impact strength by 17.9 and 30% respectively, compared to the PVC/CPE blends. Differential scanning calorimetry analysis indicated that the miscibility of PVC/CPE-cg-HEA was better than that of PVC/CPE. An analysis of morphological structure showed that the grafting component of PHEA onto CPE promoted amalgamation between the primary particles of PVC and CPE-cgHEA. Further research suggested that the toughening mechanism of the PVC/CPE-cg-HEA blends was different from that of the PVC/CPE blends. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 86-96, 2011