The effect of modification on structure and dynamic mechanical behavior during the processing of acrylic fiber to stabilized fiber

✍ Scribed by Tse-Hao Ko; Phaichit Chiranairadul; Hsing-Yie Ting; Chung-Hua Lin

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 771 KB
• Volume: 37
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1989.070370219

✦ Synopsis

Polyacrylonitrile (PAN) fibers pretreated with potassium permanganate have reduced the time required for stabilization, and also improved mechanical properties of the reaultant carbon fibers.

In this study, the effect of modification on the stabilization process and the dynamic mechanical propertics of PAN fibers have been examined. The beta peak appeared at about 125OC on the loss tangent curves caused by molecular motion in the PAN fiber. Appearing at about 254OC, the alpha peak is attributed to chemical reactions and molecular motion in the formation of the crystalline phase of stabilized fibers. The alpha peak of the modified PAN fiber had lower absorption and had a smaller peak in the temperature range of 212-239°C. This indicated that potasium permanganate acts as a catalyst to lower the reaction temperature by about 2OoC of the initial cyclization reaction. The dynamic storage modulus analysis indicated that modified PAN fibers have a lower initial transition temperature and that formation of the ladder polymer is gradual and steady.