PAN基碳纤维低温碳化过程中组分演变规律

Composition Evolution of PAN Based Carbon Fiber During Low Temperature Carbonization

采用连续预氧化、碳化制备方法,对PAN纤维低温碳化阶段不同温度条件下的纤维进行DSC、线密度和元素分析等表征分析测试,研究其低温碳化过程中组分的演变规律。结果表明:预氧丝由室温进入低温炉,大约350℃时会发生瞬时热收缩,造成线密度由950g/km增加至990g/km,增加了4. 2%。在450℃时,发生热分解反应,生成丙烯腈二聚体、三聚体系列物质和小分子气体,失重30%。随着纤维逐步加热,N,H和O逐渐脱除,经碳化工序最高温度为700℃处理后纤维碳含量增加至70%。

The continuous Pre-oxidation and carbonization methods were used to characterize the PAN fibers at different temperatures during low-temperature carbonization by DSC,linear density and elemental analysis. The results show that the instantaneous heat shrinkage occurs when the pre-oxidized wire enters the cryogenic furnace from room temperature to about 350℃,resulting in linear density increased by 950 g/km to 990 g/km,increased by 4. 2%. At 450℃,thermal decomposition reaction takes place,resulting in the formation of acrylonitrile dimers,trimers and small molecule gas,and the weightlessness is aggravated 30%. As the fibers were heated gradually,N,H and O were removed,and the carbon content of the fibers increased to 70% after carbonization at 700℃.