Fig. 3.

WAXS patterns of PBIs 2, 3, and 4. WAXS diffraction pattern of aligned fibers of a,b PBI 2 at 160 °C, c,d PBI 3 at 180 °C, and e,f PBI 4 at 224 °C. The relative position of the fibers are indicated by yellow arrows and the meridian and equator by white dashed lines. The reflections on the equator are indexed according to Col_h or Col_r phases in Fig. 2. The reflections on the meridian that are attributed to layer lines are indicated as L = X. Dashed green lines indicate additional diffuse reflections at small angles