ULTRASONIC (XAJUCI'EBIZATION OF POLYMERS AS PIJNCTION OF TIPIPERATLJRE, PRESSURE AND FREQUENCY

We present an ultrasonic technique for the thermomechanical analysis of polymers. The method yields a simultaneous measurement of specific volume (V), sound velocity (v) and attenuation (a). This allows a discussion of the characteristics of propagation with regards to the well defined thermodynamical state for the material. The measurements were made on controlling the thermodynamic history in the range of temperatures from -150OC to 3OO0C and pressures up to 1 Kbar. Our results demonstrate that ultrasound constitutes a useful probe of the quantities that are relevant to the characterization of polymers for the purpose of quality or process control.