Thermal properties of acrylonitrile/itaconic acid polymers in oxidative and nonoxidative atmospheres

• Published in: Journal of applied polymer science Vol. 116; no. 2; pp. 1207 - 1212
• Main Authors: Yu, Meijie, Wang, Chengguo, Zhao, Yaqi, Zhang, Min, Wang, Weiqiang
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15-04-2010; Wiley
• Subjects: Applied sciences; Atmospheres; Carbon; carbon fibers; Chemical reactions and properties; Copolymers; Differential scanning calorimetry; differential scanning calorimetry (DSC); Exact sciences and technology; Fibers; Gelation; Itaconic acid; Organic polymers; Physicochemistry of polymers; polyacrylonitrile; Reproduction; Stabilization; Thermal properties; thermogravimetric analysis (TGA); Ionomer; differential scanning calorimetry (DSC); Property composition relationship; Thermooxidative degradation; Thermal stabilization; thermogravimetric analysis (TGA); Experimental study; Mineral fiber; Itaconic derivative copolymer; Precursor; Thermal stability; Polyelectrolyte; Thermal properties; Acrylonitrile copolymer; carbon fibers; Reaction mechanism; Acid copolymer; polyacrylonitrile; Thermal degradation; Carbon fiber
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.31664

Thermal stabilization of polyacrylonitrile (PAN) fibers is an indispensable process in the manufacture of carbon fibers. The effects of acidic comonomers on the thermal properties of PAN have attracted much attention because of their importance in the fibers spinning and heat treatment process. In this study, oxidative and nonoxidative atmospheres are adopted in differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) test to disclose the key effects of oxygen on the thermal properties of PAN/itaconic acid (IA) polymers. The DSC results under oxidative atmosphere are consistence to the reports by previous researchers: the exothermic curves of copolymers containing 0.6 wt % and 1.0 wt % IA exhibit lower initiation temperature and more broaden shapes than that of PAN homopolymer, indicating that IA facilitates both cyclization and oxidation reactions. However, copolymers containing the same content of IA shows no apparent improving effect on the thermal properties under inert atmosphere, which has not been mentioned in the published literature. TGA indicates that oxygen remarkably increases the thermal stability of AN/IA copolymers structure, and will bring high carbon yield in the eventual carbon fibers. The influential mechanisms of oxidative and nonoxidative atmospheres on thermal stabilization reactions of PAN were discussed.