Viscoelastic Properties of 1,2 Polybutadiene and Comparison with other Rubbers

摘要

The dynamic viscoelastic properties of polybutadiene rubber consisting of principally 1,2 microstructure are of interest to the Navy. These properties have been determined by measuring the velocity and attenuation coefficient of ultrasonic waves in the material from 300 kHz to 5 MHz and from -50C to 100C. The sound velocity was found to increase with decreasing temperature, leveling off both at high and low temperatures. This effect is attributed to the appearance of a crystalline shear elasticity at the lower temperatures. Peaks in the attenuation as a function of both temperature and frequency were observed. It was also found that the data could be represented by reduced frequency or temperature plots by assuming that the dynamic properties undergo a transition which is exponentially proportional to the fractional free volume (Williams-Landel-Ferry formularization).