氧化剂对柔性石墨材料力学性能的影响研究

采用液相氧化法制备可膨胀石墨，在10MPa下压制柔性石墨试样并测定其抗拉强度和抗压强度，考察了氧化剂的氧化性和氧化程度对柔性石墨力学性能的影响，探讨了柔性石墨的微观结构和内部孔结构与其力学性能的关系。结果表明：柔性石墨材料的抗拉强度和抗压强度随氧化剂氧化性的提高而增大，氧化程度过高和过低都不利于获得高力学性能的柔性石墨材料。通过工艺优化可得到抗拉强度为4．02MPa、抗压强度为52．3MPa的高性能柔性石墨。膨胀石墨的微观结构和内部孔结构对柔性石墨的力学性能有较大的影响，膨胀率较高的膨胀石墨孔隙细长、孔径较大、开孔数量较多，在压制过程中孔隙内的气体容易排除，所得柔性石墨的气孔数目少，体积小，因而具有较高的力学性能。

THE EFFECT OF OXIDANT ON MECHANICAL PROPERTIES OF FLEXIBLE GRAPHITE

The expandable graphite samples were synthesized by chemical method ,the flexible graphite samples were manufactured under 10 MPa. The tensile strength and compressive strength were measured,the influence of different oxidants on the mechanical properties of the graphite materials were investigated ,interior microstructure and hole structure were analyzed,the effect of oxideation and interior microstructure on the mechanical properties were also studied. The results indicate that the tensile strength and compressive strength of flexible graphite increase with oxidizability of the oxidants. Both excessive and inadequate oxidation result in decrease of the mechanical properties of the flexible graphite. The tensile strength and the compressive strength of the flexible graphite sample manufactured through process optimization,are 4. 02MPa and 52.3MPa,resperlively. The mechanical properties of the flexible graphite are also related to its interior microstructure and hole structure. The samples of high expansion rati have relatively slim and long holes ,bigger diameter of holes ,more unlocked holes. Therefore ,the air which inhabits the interior holes is prone to exclude during the pressing of the samples. The products have relatively less interior air holes and volume,as a result the high mechanical properties of the graphite materials can be obtained.