Acoustic and dynamic mechanical properties of a polyurethane rubber

Abstract

Acoustical and dynamic mechanical measurements were carried out on a commercial polyurethane rubber, DeSoto PR1547. The sound speed and attenuation were measured over the range from 12.5 to 75 kHz and 3.9 to 33.6 degrees C. Shear modulus was measured from 10(-4) to 2 Hz and -36 to 34 degrees C. The peak heights of the shear loss tangent varied with temperature, demonstrating thermorheological complexity. At higher temperatures, time-temperature superpositioning could be applied, with the shift factors following the Williams-Landel-Ferry equation. From the combined acoustical and mechanical measurements, values for the dynamic bulk modulus were determined. Moreover, superposition of the bulk modulus data was achieved using the shift factors determined from the dynamic mechanical shear measurements. Finally, this work illustrates the capability and the working rules of acoustical measurements in a small tank.

Ultrasonic properties of fly ash/polyurea composites

“…However, it is interesting to note that the bulk modulus of pure polyurea ( Fig.10 (a)) decreases as the Poisson's ratio approaching 1/2. This is consistent with the observation of Mott et al [27] on polyurethane. Adding FA particles decreases the Poisson's ratio of the system significantly.…”

Supersonic rupture of rubber

“…The reason is that dissipation in real amorphous solids is not of the form employed here, nor is there any simple way to correct the deficiency. The spatial decay rate of sound waves in rubber over frequencies ranging from kilohertz to megahertz is roughly linear in o (Mott et al, 2002) …”

Locally resonant phononic woodpile: A wide band anomalous underwater acoustic absorbing material

“…Their sound absorbing behaviors have been well studied in the literatures. [19][20][21][22] The underwater acoustic absorption capability of the LRPW is much better than that of traditional underwater acoustic absorbing materials at measured spectrum. The strong acoustic absorption characteristic of the LRPW is not originated by a certain component or simple linear superposition of acoustic absorption from its separate components.…”