Shear viscosity of inorganic glasses and polymers

The viscosity of metaphosphate glasses and polystyrene was measured in the shear deformation mode above and below the glass transition temperature Tg. The temperature dependence of the viscosity above Tg was well expressed by the Vogel-Tammann-Fulcher formula, while two relaxations of thermal activation type appeared below Tg. The overall temperature dependence in both materials was very similar with each other. The relaxation at the lower temperature was found to be sensitive to the internal state of the materials.