Wayne T. Reader N. Scott Emery Lois S. Pena
Vector Res. Co., Inc., 2101 E. Jefferson St., Ste. 700, Rockville, MD 20852
Investigators actively engaged in the measurement of the moduli and loss factors of viscoelastic polymers are well aware of the diversity of results obtained by different measurement techniques---even though the specimens are fabricated to be identical. To alleviate this perennial problem, the ASA has sponsored working group S2WG79 to identify several polymers for use in calibration of the multitude of apparatuses being used to characterize dynamic moduli and loss factors. Criteria used to select candidate polymers include ready availability, property stability, bondability to mounting blocks, versatility to cover wide frequency and temperature ranges, manufacturing repeatability, and, most important, rheological simplicity. Three candidate polymers have been proposed and distributed for initial evaluation. Evaluations of how these candidates performed on a Polymer Laboratories DMTA will be presented, and their suitability for standard materials as determined by the selection criteria will be addressed.