无硫可膨胀石墨的制备及机理研究

Studies on Preparation and Mechanism of Sulfur-free Expandable Graphite

采用化学方法制备了无硫可膨胀石墨,并对其最佳工艺条件进行了探讨。以高锰酸钾为氧化剂,以硝酸和磷酸为插入剂,以天然鳞片石墨为基质制备了无硫可膨胀石墨。制备的适宜条件为石墨(g)∶混酸(ml)∶高锰酸钾(g)=1.0∶10∶0.2,反应温度45℃,反应时间为80min。所得到的无硫可膨胀石墨经水洗至pH值为5～7,烘干后在900℃～1000℃的高温下膨胀,即得无硫膨胀石墨。与已有方法相比,用此法制备的膨胀石墨不含硫,膨胀倍率高,膨胀充分。

The preparation of stlfur-free expandable graphite using a chemical method was studied to determine the optimum conditions. The sulfur-tree expandable graphite has successfully prepared by KMnO4 as oxidant and HNO3, H3PO4 as inserting agent based on the raw flaky graphite in this paper. The optimized experimental conditions as follows： the raw flaky graphite（g） ： the mixture acid（ml） ： potassium permanganate（g）=1.0 ： 10 ： 0.2, the reaction time is 80 minutes at 45℃. Finally, alter washing in water to a pH 5-7 and drying, expand it in the temperature range 900-1000℃, then the expand graphite has prepared. The method is simple and has advantages over present methods in that the sulfur-free and not only has high expanding volume, but also has fully expanded.