| Abstract: | The dynamic mechanical properties of poly-4-methylpentene-1 have been measured in torsion in the temperature range from 25 to 160°C. at frequencies from 10?3 to 10 cps. Two transitions are found. The first, with a peak at 40°C. at 1 cps, appears as a normal glass transition. A broad high temperature peak appears at 130°C. The dynamic compliance-frequency data can be superposed by the conventional method of reduced variables for temperatures up to 100°C. The temperature dependence of the shift factors follows the WLF equation. Above this temperature, superposition can be achieved by applying horizontal and vertical shifts to both components of the dynamic compliance. When the vertical shift is permitted, the range of applicability of the WLF equation is extended to 160°C. |
