对位芳纶磷酸化表面改性

为提高芳纶与基质材料的黏结性能。采用稀磷酸在芳纶表面进行高温浓缩磷酸化改性。结果表明：稀磷酸高温浓缩工艺能够对纤维表面进行有效的改性；XPS分析表明：稀磷酸浓缩改性可以在芳纶表面引入大量的磷元素；SEM分析表明：芳纶改性后，表面由光滑变为略微粗糙；红外光谱分析表明：芳纶纤维的改性使纤维表面引入了-P-OH，31P-NMR分析表明:改性芳纶结构中引入了二磷酸基团；X射线衍射和热失重分析表明：改性后的芳纶结晶结构没有变化，结晶度略有增加，热稳定性保持良好；在低磷酸浓度条件下，改性后的芳纶纤维力学性能保持良好。稀磷酸浓缩改性工艺流程短、改性速度快、成本低、具有良好的应用前景。

Surface modification of para-aramid fiber by phosphoric acid

The surface of para aramid fiber (Twaron) is required to be modified to improve the bonding property between aramid fiber and matrix material. So the research of phosphorylated surface modification of para aramid fiber by dilute phosphoric acid which was concentrated gradually under high temperature has been done. The research results showed that the method of dilute phosphoric acid concentrated under high temperature could modify aramid fiber effectively; XPS analysis showed that surface modification of aramid fiber by concentrated dilute phosphoric acid can introduce a large amount of phosphorus; SEM analysis showed that the surface of fiber changed from smooth to a slightly rough after modification; infrared spectrum analysis indicated that -P-OH was introduced to the surface of aramid fiber through modification, 31P-NMR analysis indicated that diphosphate groups were introduced in the structure of the modified aramid fiber; X ray diffraction and thermal gravity analysis showed that the crystal structure of modified aramid fiber didn’t change, the crystallinity of fiber increased and it maintained good thermal stability ; the modified aramid fiber kept good mechanical properties in low concentration of phosphoric acid. The technique of dilute phosphoric acid concentrated under high temperature has the advantages of short process、high velocity of modification、low cost, and has a good application prospect.