Influence of physical aging at constant temperature on the shear creep of amorphous polymers

Abstract

The theory of linear viscoelastic behaviour under the influence of aging at constant temperature is briefly reviewed. Emphasis is placed on the evaluation of the retardation time — age shift relation from creep experiments under proceeding aging.

The shear behaviour of a technical polystyrene was carefully measured at four temperatures just below the glass transition temperature, systematically varying the time elapsed between the temperature quench and the start of the creep experiment. The results could be accurately described by Struik’s theory of viscoelastic behaviour under aging. The dependence of the retardation times on age and temperature in the vicinity of the glass transition is discussed.