Acrylonitrile (AN)-acrylamide (AM) copolymers were prepared by nitric acidic hydrolysis of homopolyacrylonitrile. The acrylamino group increased as a function of hydrolysis time, while crystallinity decreased. Differential scanning calorimetry and a thermal gravimetric analysis indicated that the acylamino introduced by acidic hydrolysis effectively enhanced the cyclization reaction at low temperature due to the change of the cyclization reaction mechanism. Char-yield of AN-AM copolymers also gradually increased with increasing hydrolysis time. The maximum char-yield was 49.48% when hydrolized at 23°C in 65% nitric acid solution for 18 h, which was 30% higher than that of non-acidic hydrolysis of homopolyacrylonitrile. Simulation of the practical process also showed an increase of char yields, where the char yields were 55.43% and 62.60% for homopolyacrylonitrile and copolyacrylonitrile, respectively, with a hydrolysis time of 13 h.

• Run Cheng(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)
• You Zhou(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology)
• Jing Wang(Department of Chemistry and Chemical Engineering, Anyang Normal University)
• Yumin Cheng(Department of Chemistry and Chemical Engineering, Anyang Normal University)
• Seungkon Ryu(Department of Chemical Engineering, Chungnam National University)
• Riguang Jin(State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology) Corresponding Author