Mechanical properties and superstructure of poly(ethylene terephthalate) fibers zone-drawn and zone-annealed by CO2 laser heating

✍ Scribed by Akihiro Suzuki; Noriaki Mochiduki

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 226 KB
• Volume: 82
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.2131

✦ Synopsis

Abstract

A laser‐heating zone‐drawing and zone‐annealing method using a continuous‐wave carbon dioxide laser was applied to poly(ethylene terephthalate) (PET) fiber to improve its mechanical properties. The as‐spun fiber was zone‐drawn under a applied tension (σ~a~) of 4.44 MPa at a laser power density (PD) of 6.08 W cm^−2^, and then the laser‐heated zone‐drawn fiber was zone‐annealed. The laser‐heating zone‐annealing was carried out in three steps: the first annealing was carried out under σ~a~ = 139 MPa at 4.83 W cm^−2^; the second annealing was carried out under σ~a~ = 283 MPa at 4.83 W cm^−2^, and the third annealing was carried out under σ~a~ = 432 MPa at 3.45 W cm^−2^. The surface temperature distribution of the fiber irradiated with the CO~2~ laser was measured by using an infrared thermographic camera equipped with a magnifying lens. The relation between the laser power and the surface temperature of the fiber became clear in the laser‐heating zone‐drawing and the laser‐heating zone‐annealing. The fiber obtained finally had a birefringence of 0.239, a degree of crystallinity of 55%, a tensile modulus of 19.8 GPa, and a storage modulus of 25.7 GPa at 25°C. In FTIR measurements, a trans conformation increased with the processing, but a gauche one decreased. The laser‐heating zone‐drawing and zone‐annealing method was found to be effective in producing the PET fiber with high modulus and high strength. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2775–2783, 2001