Abstract: The mechanical and rheological properties, heat resistance, and microscopic structure of CPVC/ASA blends were studied. With increasing ASA contents, the tensile strength and heat resistance of the blends decreased, however, the cantilever notched impact strength increased, in addition reduced the balance torque in the plasticizing testing. At an ASA content of 30 phr, the impact strength was 11.18 kJ/m2，the tensile strength was 48.64 MPa, Vicat softening point was 105.4 ℃, balance torque was 21.4 N·m, which was 7 N·m lower than that of neat CPVC.

Key words: acrylonitrile - styrene - acrylate copolymer, blend, heat resistance, CPVC/ASA blend, mechanical property, rheological property, microscopic structure