Effects of Absorbed Benzene on Relaxation Behavior of Polytrifluoroethylene

Abstract

Relaxation behavior in polytrifluoroethylene (PTrFE) with varied crystallinity and swollen with benzene was investigated by mechanical and dielectric measurements. PTrFE showed the α, β, and β′ relaxation in decreasing order of temperature. The β relaxation observed around –20°C at 100 Hz was considered to consist of two components assigned to the amorphous and crystalline regions. The β′ relaxation found in a lower temperature region below –50°C was related to molecular motions around the defects of anomalous linkages such as head-to-head and tail-to-tail. In swollen PTrFE, the α relaxation due to the micro-Brownian motions of main chains shifted from 50°C to –10—0°C in mechanical measurements. The β relaxation for swollen samples decreased in intensity or vanished. This was interpreted by considering that the component assigned to the amorphous regions did not occur or was concealed by the α relaxation shifted to lower temperature. Relaxation behavior of the component assigned to the crystalline regions was revealed in swollen samples and related to reorientation of chains adjacent to the row vacancy defects at chain end.