Determination of Visco-elastic Properties of Dental Polymers by Mechanical Impedance Measurements

A mechanical impedance method has been used to determine visco-elastic properties, namely, Young's Modulus (E) and the mechanical loss tangent (Tan δ), at a nominal temperature of 23° C and over the frequency range 0.02 - 20 k Hz. This method involves longitudinal wave propagation in a rod of material, and measuring resonant frequencies and half-band widths. Both glassy and elastomeric polymers have been studied, and data have been compared with low frequency and static data.