Kevlar 49纤维与芳纶Ⅲ的结构与性能研究

Structure and properties of Kevlar 49 fiber and aramid fiber Ⅲ

借助傅立叶变换红外光谱仪、扫描电子显微镜、X射线光电子能谱仪和强力拉伸仪分析研究了Kevlar 49和芳纶Ⅲ的化学结构、表面特征及力学性能。结果表明:芳纶Ⅲ的红外谱图上多出了苯并咪唑环的吸收峰;芳纶Ⅲ的表面较粗糙,Kevlar 49表面较光滑,芳纶Ⅲ和Kevlar 49纤维表面的碳、氧元素均比化学式计算值有所增加,但氮元素含量下降;芳纶Ⅲ表面的极性基团种类比Kevlar 49多。芳纶Ⅲ的单纤维拉伸强度是Kevlar 49的1.5倍,断裂伸长率比Kevlar49提高了45%～65%;2种纤维的断裂方式均为劈裂断裂,具有皮芯结构,但芳纶Ⅲ分子间的作用力比Kevlar49纤维强。

The chemical structure,surface characteristics and mechanical properties of Kevlar 49 fiber and aramid fiberⅢwere analyzed with Fourier transform infrared detector,scanning electron microscope,X-ray photoelectron spectrometer and tensile strength tester.The results showed that the absorption peak of benzimidazole ring appeared in the IR spectrum of aramid fiberⅢ;the surface of aramid fiberⅢwas relatively rough when the surface of Kevlar 49 fiber was relatively smooth;the carbon and oxygen elements content were higher and the nitrogen element content was lower than those values on the surface of aramid fiberⅢand Kevlar 49 fiber calculated according to the chemical formulas;the varieties of polar groups on the surface of aramid fiberⅢwere more than those on the surface of Kevlar 49 fiber.The tensile strength of single aramid fiberⅢwas 1.5 times as high as that of Kevlar 49 fiber and the elongation at break was 45%- 65%higher than that of Kevlar 49 fiber.The cleavage fractures of these two fibers were attributed to their sheath-core structure crack and aramid fiberⅢexhibited the intermolecular force stronger than Kevlar 49 fiber.