中文摘要：

以对苯二甲酸（PTA）、间苯二甲酸（IPA）和硫酸肼为主要原料，通过一步法合成了聚对／间苯噁二唑（p／m—POD），并使用湿法纺丝制备出了耐高温的纤维。通过各种表征方法研究了IPA的引入对纤维热稳定性能、力学性能、耐酸碱性的影响。通过与p-POD的对比，结果表明引入IPA能够使POD的环化率由70％提高到90％，当IPA的含量不超过10％时，其热稳定性能不会出现降低。IPA的加入能明显地提高纤维的耐酸性，POD3纤维在30％H2SO4中，100h后仍有55％的强度保留率。

英文摘要：

Poly （p/m-phenylene-1, 3, 4-oxadiazoles）, p/m-POD was prepared by random copolymerization of terephthalic acid （PTA） and isophthalic acid （IPA） with hydrazine sulfate. The p/m-PODs with different IPA content were spun to fiber via wet spinning procedure. The thermal stability, mechanical properties and chemical resistance of the fibers were studied. The results show that when the introduction of IPA to POD increases the cyclization degree of POD from 70 % to 90 %, and the thermal stability of POD is also good enough when the IPA content is less than 10%. Furthermore, the incorporation of IPA can improve tensile retention of the POD in acid environment by large extent. For POD3, the ultimate tensile strength decreases only 45 % after immersed in 30 % H2SO4 for 100 hours.