LIMIT OF LINEAR VISCOELASTIC RESPONSE IN POLYMER MELTS AS MEASURED IN MAXWELL ORTHOGONAL RHEOMETER

The Maxwell orthogonal rheometer was used to measure the limit of linear voscoelasstic reponse (LLVER) as a function of frequency for three polymers. Two constitutive equations are noted for the dependence they predict of the strain LLVER as a function of frequency. Data are shown to support Tanner's theory. Plots of the reduced in-phase modulus, and the reduced in-phase viscosity, versus strain, yield very similar curves for all the polymers. The reduced in-phase modulus is constant as the strain is increased up to the elastic LLVER.