超薄预浸料对碳纤维/环氧树脂复合材料导电性能的影响

Effect of ultra-thin prepreg on conductive properties of carbon fiber/epoxy composites

为了协同提高碳纤维/环氧树脂(CF/EP)复合材料的电性能和力学性能,采用碳纤维丝束展宽、浸润一体化的工艺方法,将12K CF展宽预浸制备成厚度分别为0.02 mm、0.03 mm、0.08 mm、0.10 mm的CF/EP预浸料及其单向层合板,分析测试了微观结构尺度对CF/EP复合材料层合板电阻率、电阻率随温度及在拉伸载荷作用下响应的影响机制。结果表明,随着CF/EP预浸料厚度从0.10 mm减小到0.02 mm,CF/EP复合材料单向层合板中大尺度树脂富集区所占比例明显减小,厚度方向的电阻率从151.3Ω·cm减小到32.1Ω·cm,导电性能提高了约5倍;随着温度升高,CF/EP复合材料层合板电阻率逐步下降,厚预浸料层合板沿厚度方向电阻率的下降速率高于薄预浸料层合板;在载荷作用下由CF/EP薄预浸料制成的CF/EP复合材料层合板的电阻率具有较高的稳定性,表明预浸料薄层化有助于提高CF/EP复合材料抵抗载荷作用的能力,从而获得较高的力学性能和电性能。实验结果为CF/EP复合材料结构-功能一体化设计提供了基础。

In order to improve the electrical and mechanical properties of carbon fiber/epoxy(CF/EP)composite,the 12 K CF was prepared into CF/EP prepreg using the integrated process of carbon fiber spreading and infiltration.The thickness of CF/EP prepreg was 0.02 mm,0.03 mm,0.08 mm and 0.10 mm,respectively.Then CF/EP composite unidirectional laminate was fabricated by the molding process.The influence of the microstructure structure on the resistivity of CF/EP composite laminate,the resistivity of the CF/EP composite laminate as a function of temperature and the response of the laminate resistivity under tensile load were analyzed and tested.The results show that the proportion of the resin-rich pocket with larger area in the CF/EP composite unidirectional laminate is reduced as the prepreg thickness is reduced from 0.10 mm to 0.02 mm,and the resistivity of the CF/EP composite along the thickness direction decreases from 151.3Ω·cm to 32.1Ω·cm.This improves the electrical conductivity of CF/EP composite by about 5 times.As the temperature increases,the resistivity of the CF/EP composite laminate decreases gradually,and the rate of resistivity declination of the thick prepreg laminate in the thickness direction is larger than that of the thin prepreg laminate.The resistivity of the CF/EP composite laminate made of thin prepreg under loading has high stability,indicating that the thin layer of prepreg helps to improve the electrical properties of CF/EP composite and the ability of load bearing,thus obtaining higher mechanical properties and electrical properties.The experimental results provide the basis for the structure-functional integration design of the CF/EP composite.