PAN纤维预氧化过程含氮结构的演变  

Evolution of nitrogen structure in PAN fiber during preoxidization process

作　　者：禹凡 王宇[1] 童元建[1] 徐樑华[1] 

机构地区：[1]教育部碳纤维及功能高分子重点实验室,北京化工大学,北京100029

出　　处：《化工新型材料》2016年第6期199-201,共3页New Chemical Materials

基　　金：国家"973"计划(2011CB605602)

摘　　要：采用红外、13 C核磁共振确定了聚丙烯腈预氧化纤维中氮的存在特征,采用X射线光电子能谱(XPS)测试了纤维中不同结合态氮的相对含量。通过对聚丙烯腈纤维进行不同温度、时间热处理,研究了纤维中不同结合态氮相对含量随温度时间的变化规律。结果表明:较低温度下(<210℃)纤维中氮以未反应氰基(—C≡N)、共轭亚胺(—CC—CN—)及烯胺(C—NH—)形式存在,当温度高于210℃,烯胺结构中的氮转变为含氧吡啶环中的氮;延长预氧化时间有利于烯胺含量的累积,纤维结构中烯胺结构有利于氧原子与纤维环结构的结合。FT-IR and 13 C-NMR were used to determine the nitrogen structures in the pre-oxidized polyacrynitrile（PAN）fibers,and XPS was used to characterize the relative content of nitrogen structures.By treating PAN fibers at different temperatures and time,the relative contents of different combination forms of nitrogen in the fibers were studied.The results showed that the nitrogen existed in forms of cyano（—C≡N）,conjugate imine（—C≡C—C≡N—）and enamine（≡C—NH—）below 210℃,and the enamine structure in the fiber transformed to the oxygen-containing pyridine ring.The relative content of enamine structure increased with increasing of pre-oxidation time.The more the enamine structure in the fiber,the easier the structure to combine oxygen in the atomosphere.

关 键 词：PAN纤维 预氧化 氮结构 XPS 

分 类 号：TQ342.31[化学工程—化纤工业]