Dynamic mechanical behaviour of chlorinated polyethylene

Abstract

Abstract Dynamic mechanical measurements of chlorinated polyethylenes with chlorine contents ranging from 5,4 to 31 wt.‐% were carried out using a dynamic viscoelastometer. The complex modulus and loss factor were determined at four frequencies in the temperature range from −150°C to 100°C. Two relaxation processes (α and γ) were observed. The first one occurs at temperatures ranging from 21°C to 40°C, depending on the chlorine content; there is a minimum in the temperature of the α process at about 20 wt.‐% of chlorine. The activation energies for this α process are higher than 100 kcal/mol, and therefore this α relaxation is considered to be different from the α relaxation in linear polyethylene. On the other hand, the α relaxation of chlorinated polyethylenes is similar to that of the parent polyethylene, taking place at temperatures ranging from −137°C to −116°C (at 3,5 Hz). The activation energies for this α process range from 14 to 26 kcal/mol (1 kcal = 4,184 kJ).