无硫膨胀石墨的制备及性能表征

针对传统方法制得的膨胀石墨含硫量高和膨胀容积不稳定的问题,以0.28 mm的鳞片石墨为原料,KMnO4为氧化剂,HClO4和H3PO4为插层剂,经微波炉和马弗炉两种膨胀方式对可膨胀石墨的膨胀容积进行测试,采用正交实验法确定了最佳工艺条件.结果表明:在石墨(g)∶混酸(mL)∶高锰酸钾(g)=1∶4.5 mL(3.6 mL高氯酸∶0.9 mL磷酸)∶0.3,反应温度30 ℃,反应时间60 min,抽滤洗涤至pH值为5~7,80 ℃干燥,于微波炉中高温膨胀,膨胀容积最大,可达350 mL/g.

Preparation and Characterization of Sulphur-free Expanded Graphite

For the high sulfur content of expanded graphite prepared and an unstable expansion volume by the traditional method, natural graphite flake graphite was used as raw material, KMnO4 as oxidant, HClO4 and H3PO4 as intercalating agent, the expansion of expandable graphite by microwave oven and muffle furnace.The orthogonal experiment was used to determine the optimum process conditions.The results show that the optimum reaction conditions are as follows: graphite (g)∶mixed acid (mL)∶potassium permanganate (g) =1∶4.5 mL (3.6 mL perchloric acid∶0.9 mL phosphoric acid)∶0.3, reaction temperature 30 ℃, reaction time 60 min, filtering and washing to pH 5-7, drying at 80 ℃, and expanding in the microwave oven, the expanded graphite has the largest volume of 350 mL/g.