This paper is concerned with an experimental study of the the influence of
physical aging and temperature on the creep deformation of epoxy resin. Mas
ter curves for various aging conditions were found to collapse into a singl
e smooth curve corresponding to a reference aging condition after suitable
horizontal translation. It is proposed that the resulting curve be designat
ed the 'master-master curve' and the corresponding time scale the 'reduced-
reduced time'. In addition, the amount of horizontal translation, the aging
parameter, can be used to estimate the aging process. We have also shown t
hat there is one-to-one correspondence between the aging parameter and poly
mer density.