中文摘要：

采用氟气（F2）对聚（对亚苯基-1，3，4-噁二唑）（p-POD）纤维表面进行直接氟化处理．衰减全反射红外光谱（ATR-FTIR）和表面电子能谱（XPS）的结果显示，通过直接氟化处理，p-POD纤维较易与F，发生反应，表面大分子链上引入了大量C-F键，表面氟元素含量高达28．2％，且F原子以-CF／C-O、-CFH及-CF2形式存在，表明在表面氟化过程中，既有取代反应，也有加成反应．热失重（TGA）结果表明氟化前后P-POD纤维的耐高温性能没有受到影响，X射线衍射图谱（XRD）表明氟化后纤维的聚集态有序性略微增加．氟化前后纤维的断裂强度基本无变化，在体积分数为20％的硫酸溶液中的人工加速酸老化条件下，氟化后纤维在老化120h后的断裂强力保留率在80％以上，相比氟化前的纤维提高了约90％，即耐酸性得到明显改善．推测表面氟化处理改善p-POD纤维耐酸性的机理是氟化后p-POD纤维表面N元素含量降低，抑制了溶剂化过程；纤维表面致密程度得到提高以及F原子与酸液形成氢键，从而阻止噁二唑环的质子化，延缓了老化进程．

英文摘要：

The surface of poly （p-phenylene-1,3,4-oxadiazole） （p-POD） fiber was fluorinated directly by fluoride （F2）. The results of ATR-infrared spectroscopic analysis and X-ray photoelectron spectroscopy（XPS） show that it can effectively generate chemical reactions between p-POD fiber and F2. A mass of C-F bonds are formed on the macromolecules of fiber surface and the content of F in the form of -CF/C = O,-CFH and -CF2 is 28.2% ,which indicates that there are not only substitution reactions but also addition reactions between p-PODs and F2. The curves of thermal gravimetric analysis （TGA） show that there is not impact on p- POD＇s resistance to high temperature,while the aggregative structures of the fluorinated p-POD fiber are more orderly than those of the original fiber from the wide angle X-ray diffraction pattern. In addition, it takes no change in strength of p-POD fiber after fluorination. Under the condition of 20% concentration sulfuric acid which belongs to the artificial accelerated aging test, the retention of strength of fluorinated p-POD fiber remains 84% which increases by about 90% compared to that of the original fiber. Thus, the acid resistance of p-POD is obviously improved owing to the hydrogen bond formed between F atoms and acid solution which makes the protonation of oxadizoles more harder. Besides,there are compact crosslinking layers formed on the surface of p-POD fiber which can slowdown the aging process.