Superstructure and mechanical properties of poly(ethylene terephthalate) fibers zone-drawn under critical necking tension

✍ Scribed by Akihiro Suzuki; Takashi Kawada

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 273 KB
• Volume: 83
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.10037

✦ Synopsis

Abstract

The superstructure and mechanical properties of poly(ethylene terephthalate) fibers zone‐drawn under a critical necking tension (σ~c~) were studied. σ~c~ was defined as the minimum tension needed to generate a neck at a given drawing temperature (T~d~) and was measured over a temperature range of 70–120°C. The σ~c~ value increased rapidly with decreasing T~d~ in the temperature range below 85°C, but the temperature dependence of σ~c~ was small above 85°C. The neck profile relied on T~d~, becoming more shapely with decreasing T~d~. A neck with a gradual decrease in diameter was observed in the fibers drawn at 100°C and above. The draw ratio increased significantly with increasing T~d~ above 90°C, but birefringence decreased. Density decreased gradually with increasing T~d~, and fiber drawn at 120°C had a density of 1.347 g/cc. Wide‐angle X‐ray diffraction photographs of the fibers drawn at 100°C and below showed reflections due to crystallites, but a photograph of the fiber obtained at 120°C showed a ring‐like amorphous halo. The storage modulus (E′) at 25°C increased progressively with decreasing T~d~, and the fiber drawn at 70°C had the maximum E′ value among the fibers drawn at a series of T~d~'s. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 179–185, 2002