The secondary relaxation process of poly(vinyl chloride) and its derivatives

The temperature dependence of the shear modulus G′ and of the damping tan δ of poly‐(vinyl chloride), poly(vinylidene chloride), copolymers of vinyl chloride–vinylidene chloride, PVC chlorinated in solution and suspension, and chlorinated polyethylene was measured. Secondary relaxation process of PVC and its derivatives are being explained as vibration of methylene groups polarized by neighboring CCl dipoles. This process, being suppressed by lowering the concentration of the methylene groups in the PVC chain (e.g., by chlorination), remains, however, unaffected by the growth of crystalline content. The achieved results show that in the α‐transition region there occurs, in accordance with Andrews' theory, a loosening of the bonds between the CCl dipoles, whereas in the β‐transition region a loosening of the weaker bonds among the dipoles of the polarized methylene.