热处理温度对对位芳纶纤维表面聚集态结构和性能影响

以不同温度(200,250,300,350℃)热处理对位芳纶纤维,用傅立叶变换红外光谱(FTIR)、拉曼光谱(Raman)、X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)分析了氧化热处理对对位芳纶纤维表面基团和聚集态结构的影响.FTIR和XRD分析结果表明,经250℃及以上热处理,纤维表层分...

Effects of Heat Treatment Temperature on Surface Aggregation Structure and Properties of Para-Aramid Fibers

The para-aramid fibers were heat treated at the different temperatures(200,250,300,350℃),the effects of heat treatment on the surface group and the aggregate structure of para-aramid fibers were investigated by Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and scanning electron microscope(SEM).The results of FTIR and XRD analysis show that the molecular chains in the surface layer of the fibers were rearranged and the hydrogen bonds were enhanced when the temperature is greater than or equal to 250℃.The results of Raman and XPS analysis show that C(C—C,C=C or C—H)on the surface molecular chain of p-aramid fibers are oxidized to be—C—OH or—COOH at 250℃or above,and the surface polarity of the fibers increases.After heat treatment at 300℃,the molecular chains on the surface of para-aramid fibers move,rearrange and began to shrink,the crystallinity increases,and the tensile strength of the single fiber reaches 25.7 cN/dtex,which increases by 4.9%.After heat treatment at 250℃,the interfacial shear strength of paraaramid fiber and epoxy drop reaches 18.05 MPa,which increases by 11.9%compared with the untreated fiber.