AN INVESTIGATION INTO THE STRUCTURE OF POLY(ETHYLENE-TEREPHTHALATE) FIBERS BY THE USE OF OPTICAL TRANSFORMS

An investigation has been made into the structural changes in poly(ethylene terephthalate) fibers brought about by drawing in a texturing machine. Evidence from both wide-angle and small-angle X-ray scattering is presented. The main feature of the small-angle X-ray scattering is a transition from two, meridional diffraction peaks to a symmetrical, four-point pattern as the draw ratio is increased. Optical transform methods have been used to investigate possible structural changes which could produce the observed transition. A tentative structure of poly(ethylene terephthalate) fibers is proposed.