DYNAMIC MECHANICAL AND CRYSTAL-STRAIN MEASUREMENTS ON ULTRAHIGH MODULUS ORIENTED POLYOXYMETHYLENE - REVISED VALUE FOR THE TRUE CRYSTAL MODULUS

In the reported experiments, dynamic mechanical measurements on ultrahigh modulus polyoxymethylene have been undertaken over the temperature range minus 150 to 20 degree C. Measurements of the longitudinal crystal modulus have also been made by studying changes in the (009) reflection with load, over a similar range of temperatures. The dynamic Young's modulus at 5 Hz reaches a value at low temperatures of 64. 5 GPa for the most highly oriented sample. The crystal modulus at low temperatures is 105 GPa, which is almost twice the previously reported room-temperature value.