一种制备膨胀石墨的新方法及其压制品的性能研究

A Novel Way to Fabricate Expanded Graphite and the Performance for its flexible Graphite

以粒径约0.5mm的天然鳞片石墨为宿主材料,以高氯酸液为氧化、插层剂,通过简单的酸液浸泡法直接热氧化转化天然鳞片石墨为膨胀石墨.用浓度为72%(质量分数)的高氯酸液在室温下浸泡天然鳞片石墨1～3min.后,在900下膨化,膨胀体积为549mL/g.以该条件制备的膨胀石墨为前驱体通过冷压成型的方法制备柔性石墨,利用材料万能试验机、微欧计、激光热导仪分别测试了该材料的抗拉强度、电阻率、导热率.实验结果表明:抗拉强度(T)、电阻率(ρ)同密度(d)呈线性正相关,其中T=12.1d-7.6,R=0.977;ρ=-3.97d+11.9,R=0.968.热导率同电阻率呈负相关性.

Natural flake graphite with particle size of ca 0.5mm and perchloric acid with various concentration ranging from 20%-72%(mass fracfion) were used as host material and oxidating/intercalating agents respectively to fabricate expanded graphite by direct thermooxidative conversion method.The expanded volume of flake graphite increases with the concentration of perchloric acid increasing.The expanded volume of flake graphite which was first impregnated by perchloric acid with the concentration of 72% for 1~3 min.and then exfoliated at 900 was 549 mL/g.The mechanical,electrical,thermal performances of flexible graphite with deferent densities manufactured with the expanded graphite with expanded volume of 549 mL/g were characterized by all-purpose material tester,microohmmeter and laser thermal flashmeter.The results show that tensile strength(T),electrical resistivity(ρ)have positive linear relationship with densities,respectively: T=12.1d-7.6(relationship coefficient,R=0.977);ρ=-3.97d+11.9,R=0.968.The thermal conductivity is a inverse function of electrical resistivity.