湿法成形梯度孔隙结构炭纤维纸的结构与性能

Structure and properties of wet forming carbon fiber paper with gradient porous structure

以短切炭纤维为原料,采用湿法成纸技术制备具有不同面密度的炭纤维毡片,再经双层和多层铺叠成形、树脂浸渍和热处理,获得具有梯度孔结构的炭纤维纸,用扫描电镜观察各层的孔隙结构,采用压汞法分析炭纤维纸的孔隙度和孔径分布,应用多孔分析仪测试炭纤维纸的透气率。结果表明,炭纸具有梯度层级结构,石墨化度达到93.14%,多层炭纸的平均孔隙率为75.5%,双层炭纸的平均孔隙率为81.4%。多层炭纸的透气率为5272 m/(kPa·h)、面内电阻率为11.78 mΩ·cm、抗拉强度和抗弯强度分别为20.62 MPa和60.88 MPa,均优于商业炭纸。此外,梯度孔结构炭纸在酸性介质中表现出优于商业炭纸的耐腐蚀性能。

Carbon fiber felts with different areal densities were firstly fabricated by wet process using short-cut carbon fibers as raw materials.Afterwards,carbon fiber paper(CP)with gradient porous structure was prepared through double-layer or multi-layer molding,resin impregnation and heat treatment.The pore structure,pore size distribution along with porosity and air permeability of as-prepared CP were measured by scanning electron microscope(SEM),mercury intrusion method and porous analyzer.The results show that the CP has gradient structure with graphitization degree of 93.14%.The average porosity of the multi-layer paper is 75.5%,and the average porosity of the double-layer paper is 81.4%.The air permeability,in-plane resistivity,tensile strength and flexural strength of multi-layer paper are 5272 m/(kPa·h),11.78 mΩ·cm,20.62 MPa and 60.88 MPa,respectively,exceeding those of commercial CP.In addition,CP with gradient porous structure shows superior corrosion resistance over commercial CP in acid solution.