Figure 1:

(a) Photo of stretched polystyrene in the perpendicular direction. (b) illustration of equilibrated specimens before stretching with different conformations of entangled linear (top) and ring (bottom) polymers. (c) illustration of stretched specimens with different conformations of the same (as in b) linear (top) and ring (bottom) polymers, showing the dramatic change in conformation due to stretching [18]. For clarity, we color one macromolecule with blue in each case, to emphasize its conformation in the melt.