Numerous studies have reported that good adhesion and fluorination of carbon materials in a fluoropolymer matrix enhance their electrical and mechanical properties. However, a composite reinforced with oxyfluorinated graphite has not been reported for improving mechanical properties. This paper discusses the fabrication of conductive fluorinated ethylene–propylene (FEP)/oxyfluorinated graphite (f-graphite) composite bipolar plates (BPs) via compression molding. To investigate the effects of fluorinating graphite, graphite with a large particle size of 500 μm was mixed with FEP powder with a small particle size of 8 μm through ball milling. The FEP/graphite composites exhibited high anisotropic electrical conductivity with the in-plane conductivity much higher than the through-plane conductivity because of the planar orientation of the graphite sheets. Therefore, the mechanical properties of the composites such as flexural strength tended to deteriorate with increasing graphite content. In particular, the FEP/f-graphite composites exhibited excellent flexural strength of 12 MPa, much higher than that of FEP/graphite composites at 9 MPa with a graphite content of 80 wt%. The interfacial interaction between FEP and f-graphite led to improved physical compatibilization, which contributed to enhance the mechanical properties of these composites. Our results are a step toward developing BPs for use in high-temperature fuel cells and heat-sink components.Graphic abstract

中文翻译：

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氟氧化石墨对氟乙烯-丙烯复合材料双极板的影响

大量研究报告称，含氟聚合物基体中碳材料的良好粘合性和氟化作用可增强其电学和机械性能。然而，尚未报道用氧氟化石墨增强的复合材料可改善机械性能。本文讨论了通过压缩成型法制备导电氟化乙烯-丙烯（FEP）/氧氟化石墨（f-石墨）复合双极板（BPs）。为了研究氟化石墨的效果，通过球磨将500μm大粒径的石墨与8μm小粒径的FEP粉末混合。由于石墨片的平面取向，FEP /石墨复合材料表现出高的各向异性电导率，其中面内电导率比通面电导率高得多。因此，随着石墨含量的增加，复合材料的机械性能例如挠曲强度趋于恶化。特别地，FEP / f-石墨复合物表现出优异的12MPa的抗弯强度，远高于9MPa下具有80wt％的石墨含量的FEP /石墨复合物的抗弯强度。FEP和f-石墨之间的界面相互作用导致改善的物理相容性，从而有助于增强这些复合材料的机械性能。我们的结果是朝着开发用于高温燃料电池和散热器组件的BP迈出了一步。随着石墨含量的增加，复合材料的机械性能（如弯曲强度）趋于下降。特别地，FEP / f-石墨复合物表现出优异的12MPa的抗弯强度，远高于9MPa下具有80wt％的石墨含量的FEP /石墨复合物的抗弯强度。FEP和f-石墨之间的界面相互作用导致改善的物理相容性，从而有助于增强这些复合材料的机械性能。我们的结果是朝着开发用于高温燃料电池和散热器组件的BP迈出了一步。随着石墨含量的增加，复合材料的机械性能（如弯曲强度）趋于下降。特别地，FEP / f-石墨复合物表现出优异的12MPa的抗弯强度，远高于9MPa下具有80wt％的石墨含量的FEP /石墨复合物的抗弯强度。FEP和f-石墨之间的界面相互作用导致改善的物理相容性，从而有助于增强这些复合材料的机械性能。我们的结果是朝着开发用于高温燃料电池和散热器组件的BP迈出了一步。石墨含量为80 wt％时，在9 MPa下比FEP /石墨复合材料高得多。FEP和f-石墨之间的界面相互作用导致改善的物理相容性，从而有助于增强这些复合材料的机械性能。我们的结果是朝着开发用于高温燃料电池和散热器组件的BP迈出了一步。石墨含量为80 wt％时，在9 MPa下比FEP /石墨复合材料高得多。FEP和f-石墨之间的界面相互作用导致改善的物理相容性，从而有助于增强这些复合材料的机械性能。我们的结果是朝着开发用于高温燃料电池和散热器组件的BP迈出了一步。图形摘要