Characterization of strain-induced crystallization of poly(ethylene terephthalate) at fast draw rates using synchrotron radiation

Online wide‐angle X‐ray diffraction/small‐angle X‐ray scattering measurements for the CO2‐laser‐heated drawing of poly(ethylene terephthalate) fiber

“…This indicates that only a part of amorphous phase is highly oriented. This scattering should be the same as that observed for PET film by Mahendrasingam et al 20,[22][23][24] and Kawakami et al 31,32 Crystal diffraction appeared abruptly 20 ms after necking. It is not observed at all in the 17 ms diffraction image, and becomes clear in the 30 ms image.…”

“…For the drawing process, most on-line measurement studies fall into one of two categories; batch drawing under small strain rate [20][21][22][23][24][25][26][27][28][29][30][31][32] , and draw ratio dependence of continuous drawing [33][34][35][36] . In both cases, x-ray diffraction images are taken at a fixed position.…”

Flow-enhanced nucleation of poly(1-butene): Model application to short-term and continuous shear and extensional flow

“…For this reason, all flow-induced nuclei after short-term flow have the same radius at any point in time, within the resolution of an optical microscope [Hristova et al (2004); Stadlbauer et al (2004)]. Also in film drawing, it was observed that flow impedes nucleation [Blundell et al (1996[Blundell et al ( , 2000; Mahendrasingam et al (1999)]. For this reason, Steenbakkers and Peters (2011) took the time scale for nucleation s pn to be infinite during flow and zero after cessation of flow, i.e., no nucleation during flow and instant nucleation after flow.…”

Structural development of poly(ethylene terephthalate) during uniaxial stretching above the glass‐transition temperature: Study of the statistical influence of the stretching variables

“…All of the other conditions gave rise to an amorphous halo, although in some cases, the intensity profile seemed to concentrate at the equator region; this suggested the existence of some polymer chain orientation in the stretching direction and the presence of some content of mesophase, as reported elsewhere. 39,43,45,47,49 Although we expected to have amorphous halos in the C1, C2, C3, and C4 conditions, because the material was stretched to only 1.6Â, C6 and C8 were stretched to a much higher stretching level (2.1Â) and still presented amorphous halos. This result showed that the temperature had an important role in the structural development of the sample, and in these cases, it hindered the strain-induced crystallization mechanism of PET because of a possible competing mechanism between chain elongation due to mechanical deformation and chain relaxation due to the elevated temperature.…”