Measurement of orientation in uniaxially drawn polyacrylonitrile

In the literature, an estimate of the degree of orientation in drawn polyacrylonitrile (PAN) fibers is often inferred from the are-width of the strongest equatorial peak at 2 theta = 16.8 degrees in the wide angle X-ray diffraction pattern. The absence of sharp meridional peaks in the diffraction pattern of oriented PAN means that chain orientation-factors cannot be directly calculated. In this work, Wilchinsky's method for calculating the degree of chain orientation from the azimuthal intensity distribution of a strong equatorial peak has been adopted.