STRUCTURAL RELAXATION MONITORED BY INSTANTANEOUS SHEAR MODULUS

This paper reports on aging of the silicone oil MS704 for sudden chang es of temperature from 210.5 to 209.0 K and from 207.5 to 209.0 K stud ied by continuously monitoring the instantaneous shear modulus G infin ity. The results are interpreted within the Tool-Narayanaswamy formali sm with a reduced time definition based on a recently proposed express ion for the relaxation time, where G infinity reflects the fictive tem perature. All parameters entering the reduced time were determined fro m independent measurements of the frequency-dependent shear modulus of the equilibrium liquid.