Mechanical anisotropy in oriented polychlorotrifluoroethylene

Abstract

The dynamic tensile modulus ( E) and loss (tan δ) of various oriented samples of polychlorotrifluoroethylene have been measured at 0°, 45° and 90° to the draw direction over the range of − 100 to 160°C. For the cold-drawn samples the mechanical anisotropy at the lowest temperature is determined by the overall chain orientation resulting in E 0 > E 45 > E 90. Above the γ relaxation (20°C) a shear process is activated leading to a change in the anisotropy pattern to E 0 > E 90 > E 45. Cold-drawing followed by annealing gives rise to further changes so that E 90 > E 0 > E 45 above the β relaxation (120°C). The effect of annealing has been attributed to the relaxation of the amorphous regions and the development of lamellar texture, and the anisotropy in tan δ E at the β relaxation is found to be consistent with the interlamellar shear model.