Initial stage of fiber structure development in the continuous drawing of poly(ethylene terephthalate)

Abstract

Abstract The initial stage of fiber structure development in the continuous neck‐drawing of amorphous poly(ethylene terephthalate) fibers was analyzed by in situ wide‐angle X‐ray diffraction, small‐angle X‐ray scattering, and fiber temperature measurements. The time error of the measurements (<600 μs) was obtained by synchrotron X‐ray source and laser irradiation heating. A highly ordered fibrillar‐shaped two‐dimensional (smectic‐like) structure was found to be formed less than 1 ms after necking. By analyzing its (001′) and (002′) diffractions, the length of the structure 60–70 nm were obtained. A three‐dimensionally ordered triclinic crystal began to form with the vanishing of the structure around 1 ms after necking. The amount and size of the crystal were almost saturated within several milliseconds of necking, during which time a mainly exothermic heat of crystallization was also observed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2126–2142, 2008