Simultaneous DSC/TG analysis on the thermal behavior of PAN polymers prepared by aqueous free-radical polymerization

详细信息    查看全文

• 作者：Qin Ouyang ; ^{o_yang@126.com" class="auth_mail" title="E-mail the corresponding author} ; ^{ouyangqin@nimte.ac.cn" class="auth_mail" title="E-mail the corresponding author} ; Xiaohong Wang ; Xulan Wang ; Jing Huang ; Xianwen Huang ; Yousi Chen
• 关键词：Polyacrylonitrile ; Thermal behavior ; Thermal stabilization ; Aqueous free-radical polymerization ; Carbon fiber
• 刊名：Polymer Degradation and Stability
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：130
• 期：Complete
• 页码：320-327
• 全文大小：1225 K

文摘

A series of polyacrylonitrile (PAN) polymers with different content of itaconic acid (IA) as comonomer were prepared by an efficient aqueous free-radical polymerization technique. The thermal behavior of the PAN polymers was investigated by simultaneous DSC/TG analysis. Effects of IA content, heating rate and atmosphere on the heat release and weight loss behaviors of the PAN polymers were studied for insight of the nature of the thermo-chemical reactions. A specific triple exothermic peak was observed in the DSC curves of P(AN-IA) copolymers in air atmosphere. Three individual exothermic peaks were obtained by peak fitting and assigned to the respective thermo-chemical reactions, namely, ionic cyclization reaction, free-radical cyclization reaction and oxidation reaction. The ionic cyclization reaction was significantly influenced by the IA content. The free-radical cyclization reaction was sensitive to heating rate and atmosphere. The cyclization reaction preceded the oxidation reaction and acted as a prerequisite for the oxidation reaction. The improvement of the thermal stability of PAN was mainly attributed to the oxidation reaction through dehydrogenation and formation of oxygen-bearing groups. Mechanisms of the thermo-chemical reactions were also proposed and discussed.