Mesophase structure discovered through in-situ X-ray measurement in drawing process of poly(ethylene 2,6-naphthalene dicarboxylate) fiber

• Published in: Polymer (Guilford) Vol. 50; no. 19; pp. 4429 - 4431
• Main Authors: Kim, KyoungHou, Aida, Ryo, Kang, YoungAh, Ohkoshi, Yutaka, Gotoh, Yasuo, Nagura, Masanobu, Urakawa, Hiroshi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 10.09.2009; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Fibers and threads; Forms of application and semi-finished materials; In-situ X-ray diffraction; Laser drawing; Necking; Polymer industry, paints, wood; Technology of polymers; Laser drawing; In-situ X-ray diffraction; Necking; Hot deformation; Hot drawing; Laser heating; Naphthalate polymer; Synthetic fiber; Mesophase; Experimental study; Mechanism
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2009.07.020

The structure development in the continuous laser-heated drawing process of poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) fiber was analyzed by in-situ X-ray diffraction measurement. Because of the rapid and uniform laser heating, and the resultant steady-state nature of the necking-drawing, the structure development after the on-set of necking could be measured in the time resolution of several hundred microseconds. We found for the first time the temporal appearance of meridional (001′) diffraction at several milliseconds after the on-set of necking indicating that the mesophase structure similar to the one reported for poly(ethylene terephthalate) was also formed in the initial stage of fiber structure development of PEN. The d-spacing of the (001′) diffraction 1.230±0.003nm was shorter than the c-axis lengths of both α and β crystals. [Display omitted]