ACOUSTIC PROPERTIES OF A POLYMETACARBORANESILOXANE.

Speed of sound and absorption measurements were made on a polymetacarboranesiloxane in the temperature range from -50C to 50C and the frequency range from 92 kHz to 650 kHz. Measurements were also done on isotactic polypropylene to check out the experimental method. For polypropylene at room temperature, the measured speed of sound was 2500 msec, in satisfactory agreement with literature values. For the carborane at room temperature, the measured speed of sound was 1400 msec, typical for a rubber. Contrary to most polymers including polypropylene, however, the slope of the sound speed vs. temperature is greater below the glass transition -20 msecC than it is above the glass transition -7 msecC. Author