Chlorinated polyethylene or named CPE, which is made of HDPE by partial chlorination. Due to the existence of chlorine atom, CPE has softness and some rubber properties, and makes it a polar polymer with the same polar group as PVC, increasing the compatibility with PVC.

CPE has the function of accelerating PVC melting and plasticizing. With the increase of CPE content, the plasticizing time is shortened, the plasticizing torque and equilibrium torque are increased, and the viscosity of plasticized melt is increased. With the increase of chlorination degree, the original crystalline HDPE gradually becomes an amorphous elastomer.

The content of chlorine in CPE used as toughening agent is generally 25-45%. Besides toughening effect, chlorinated polyethylene also has cold resistance, weather resistance, fire resistance and chemical resistance,that’s why it is the leading impact modifier in China, especially in PVC pipe and profile production.