Abstract
Fibers prepared by gel-spinning of high molecular weight po]y(ethylene terephthalate) (PET) were drawn by two-step drawing. The effect of draw ratio on the crystalline structure of the gel-spun and drawn PET fibers was examined by wide and small angle X-ray diffraction analysis. With increasing draw ratio of 5-1O, both the orientation factor of crystalline chains and the crystallinity of the fiber increased slightly. On the other hand, from the attenuated total reflection IR spectrum the trans content and the dichroic function were calculated. From the results of birefringence measurement the amorphous orientation factor was also evaluated in combination with X-ray data. With increasing draw ratio of 5-1O the amorphous chain orientation was found to gradually increase. The tensile modulus and strength for the drawn fibers of IV 1.0 reached 27.5 and 1.1 GPa and those for the drawn fibers of IV 2.4 reached 28.5 and 1.3 GPa, respectively.
