A Technique to Measure the Volume of Elastomers as a Function of Temperature and Pressure with an Acoustic Pycnometer

摘要

A technique to determine the volume of elastomer samples as a function of temperature and pressure is described. The volume of butyl-252 elastomer sample is measured with an acoustic pycnometer at temperatures of 10 deg C and 25 deg C over the pressure range from 2 MPa to 70 MPa with an accuracy of better than 0.3 percent. A calibration method is used to enhance the low-pressure range of the acoustic pycnometer. The theory is developed for this calibration procedure. From the volume vs. pressure measurements, the isothermal bulk modulus is calculated at 10 deg C and 25 deg C for the butyl-252 sample. The volume of a type-W neoprene elastomer sample is also measured at 25 deg C over the indicated pressure range. (Author)