It is shown that wide-angle X-ray scattering patterns can be obtained
from single polymeric fibers with a 2 mu m synchrotron radiation beam
in a few seconds per pattern. Preferred orientation was observed for a
n ultrahigh molecular weight polyethylene fiber where orthorhombic plu
s monoclinic phases were found to coexist in the outer parts of the fi
ber. For a poly(p-phenyleneterephthalamide) fiber (Kevlar 49) the radi
al sheet model was verified, but an important texture appears to be pr
esent.