Ultrasonic detection of crosslink density in rubber vulcanizates under uniaxial compression

The velocity of longitudinal and transverse ultrasonic waves in NBR samples containing different carbon black concentrations have been measured at roo m temperature. The data have been used to determine the elastic moduli for each sample which was subjected to different compression stresses. Linear r elations were obtained between Young's modulus and compression parameters r elating the thickness of the samples before and after compression. The slop e of these linear relations were used to calculate the crosslink densities and were compared with those obtained from stress-strain measurements.