On the basis of the curves in Figure 7.26, sketch schematic strain–time plots for the foll...

On the basis of the curves in Figure 7.26, sketch schematic strain–time plots for the following polystyrene materials at the specified temperatures:

(a) Amorphous at 120°C

(b) Crosslinked at 150°C

(c) Crystalline at 230°C

(d) Crosslinked at 50°C

Figure 7.26 (a) Load versus time, where load is applied instantaneously at time ta and released at tr. For the load–time cycle in (a), the strain-versus-time responses are for totally elastic (b), viscoelastic (c), and viscous (d) behaviors.