间位芳纶的结构与耐酸碱性能研究

Structure and acid-alkali resistance of m-aramid fibers

通过X射线衍射仪和红外光谱仪分别对间位芳纶的晶体聚集态结构和大分子结构进行表征,利用场发射扫描电镜观察其表面形貌,使用热重/差示扫描量热同步热分析仪测试其热学性能,并对酸碱处理后的纤维力学性能进行表征。结果表明:间位芳纶的结晶度为46.24%,晶区轴取向指数为0.8494;间位芳纶表面粗糙,内部大分子链中存在苯环结构;间位芳纶具有良好的耐热性能,在292℃的高温内无任何损伤;间位芳纶具有一定的耐强酸强碱腐蚀能力,在85℃下分别经体积分数小于等于20%的硫酸溶液及质量分数小于等于20%的氢氧化钠溶液处理,处理后其断裂强度均保持在原来的90%以上。

The crystal aggregation structure and macromolecular structure of m-aramid fiber were characterized by X-ray diffraction and infrared spectroscopy.The surface morphology was observed by field emission scanning electron microscopy.The thermal properties were tested with a thermogravimetry/differential scanning calorimetry synchronous thermal analyzer.And the mechanical properties of the fibers were characterized after acid-alkali corrosion.The results showed that the crystallinity of the m-aramid fiber was 46.24%,and the axial orientation index of the crystal region was 0.8494;the m-aramid fibers had a rough surface and benzene ring structure in the internal macromolecular chain;the m-aramid fibers had no damage at a high temperature of 292℃,indicating a good heat resistance;and the breaking strength remained above 90%of the original when the m-aramid fiber was treated with sulfuric acid solution at a volume fraction of not higher than 20%and sodium hydroxide solution at a mass fraction of not higher than 20%at 85℃,indicating a certain resistance to strong acid and alkali corrosion.