CHARACTERIZATION OF POLYMER MELTS, RUBBER AND THERMOSETS BY MECHANICAL SPECTROSCOPY.

The term ″mechanical spectroscopy″ has been used by polymer researchers to describe the study of molecular structure with linear viscoelastic measurements. Typically the response of the dynamic shear storage or elastic modulus, G prime , and the loss modulus, G double prime , or their ratio G double prime /G prime (tan delta ) are studied over a range of frequency and temperature. This paper describes a new instrument, the Rheometrics RVE 100, which has been developed to generate mechanical spectra in the melt and rubbery region. The authors have indicated how G prime and G double prime vs. frequency spectra can be used to characterize polymer structure. They also show that dynamic stresses vs. strain can reveal effects of filler particles and dynamic data vs. time can follow reacting systems.