摘要
为实现PAN纤维在低温碳化过程的结构调控,利用核磁共振碳谱(13C-NMR)研究了PAN预氧化纤维在500～800℃的低温碳化过程中骨架结构的演变.结果表明:在低温碳化过程中,随着碳化温度的升高,预氧化纤维骨架结构中饱和的CH、CH2和C O结构逐渐消失,共轭—HC C<和>C N—逐渐减小,共轭>C C<逐渐增加,纤维形成多层多环芳香结构;多环芳香结构平均层数与碳化温度密切相关,经500、600、700、800℃碳化处理后,纤维骨架结构中多环芳香结构平均层数分别达到1.29、2.17、2.81和3.42;在较低碳化温度(500℃),多环芳香结构平均层数随碳化处理时间延长增加不明显,在较高碳化温度(700℃),多环芳香结构平均层数随碳化处理时间呈线性增加.
To better understand the mechanisms of low temperature carbonization,the evolution of skeleton structures for stabilized polyacrylonitrile（PAN） fiber during carbonization at 500～800℃ was investigated by 13C-NMR（Nuclear Magnetic Resonance）.The results showed that the saturated CH,CH2 and—C-O—groups disappeared in the stabilized fiber after carbonization.With the increasing of temperature,the conjugated—HC-C 〈and〉C-N—groups decreased,while the conjugated〉C=C〈 groups increased in the skeleton structures of the fiber.The number of layers of polycyclic aromatic structure in the fibers reached to 1.29,2.17,2.81 and 3.42 after carbonized at 500,600,700 and 800 ℃,respectively.There was no significant increase of the number of layers at 500 ℃,while linear increase of layers with time was found at 700 ℃.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2011年第6期133-137,共5页
Materials Science and Technology
基金
国家重点基础研究发展计划资助项目(2011CB605601
2011CB605602)
关键词
聚丙烯腈基碳纤维
固体核磁碳谱
骨架结构
多环芳香结构
polyacrylonitrile based carbon fiber
solid state nuclear magnetic resonance
skeleton structure
polycyclic aromatic structure
