کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5201089 | 1502883 | 2016 | 22 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Simultaneous DSC/TG analysis on the thermal behavior of PAN polymers prepared by aqueous free-radical polymerization
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 130, August 2016, Pages 320-327
Journal: Polymer Degradation and Stability - Volume 130, August 2016, Pages 320-327
نویسندگان
Qin Ouyang, Xiaohong Wang, Xulan Wang, Jing Huang, Xianwen Huang, Yousi Chen,