预环化处理方式对腈纶预氧化纤维性能的影响

研究了预环化处理方式对预氧化纤维阻燃性能和力学性能的影响。实验结果表明,先用羟胺处理,再用水合肼处理,所得预氧化纤维的阻燃性能和力学性能相对较好,在预氧化温度260℃时,可得到极限氧指数36.5%的预氧化阻燃纤维。扫描电镜观察表明,表面处理后纤维外表面裂纹明显减少,预氧化处理后纤维裂纹有所恢复。红外光谱分析表明,表面处理后纤维有少量吡啶环状结构生成,而预氧化后纤维中有大量吡啶环化结构产生。X射线衍射分析显示,经表面处理和预氧化之后纤维的形态结构没有发生大的变化,仍为高有序区和非晶区组成的准晶有序结构。

Influence of Pre-Cyclic Treatment of PAN on Properties of Pre-Oxidized PAN Fibers

This thesis researched the influence of pre-oxidized polyacrylonitrile(PAN) fiber on mechanical property and flame retardancy using cyclization pretreatment method.The results show that better mechanical property and flame retardancy of pre-oxidized polyacrylonitrile fiber can be obtained by hydroxylamine pretreatment first and hydrazine hydrates pretreatment later,when the pre-oxidation temperature is 260 ℃,the 36.5% limiting oxygen index pre-oxidized polyacrylonitrile flame retardant fibers can be obtained.Taking an ulterior step of scanning electron microscope observe,by way of surface treatment and pre-oxidation the fiber’s apparent-structure has been minor alteration;fiber’s crackle has been clear reduced after surface treatment and restitute a little bit level after pre-oxidation.Infrared spectrum shows that although a few pyridyl structures have been produced after surface treatment,a lot of pyridyl structures produced after pre-oxidation.X-ray diffraction shows that by way of surface treatment and pre-oxidation the fiber’s structure doesn’t have so much change,in some level it’s still be a quasicrystals ordered structures and composited by high lateral order and non-crystalline region.