可膨胀石墨制备工艺的对比研究

Comparative Study on Different Preparation Methods of Expandable Graphite

以攀枝花天然鳞片石墨为原材料,硫酸、硝酸和高氯酸分别为插层剂,高锰酸钾作为氧化剂制备可膨胀石墨。在最佳配比条件下,对三种工艺的干燥温度、干燥时间和膨化温度进行补充测试。结果表明采用高氯酸和高锰酸钾制备的膨胀石墨膨胀容积最大,达到185. 7 m L/g。利用XRD和SEM对天然鳞片石墨、可膨胀石墨和膨胀石墨的结构和形貌进行分析,结果也显示采用高氯酸进行插层更充分,蓬松度更好,最适用于制备复合相变材料。

Expandable graphite was prepared with natural flake graphite from Panzhihua as raw materials, potassium permanganate as oxidizing agents, and sulfuric acid, nitric acid and perchloric acid as intercalation agents. Under the optimum conditions, the influencing factors of expansion volume were explored, such as puffing temperature, drying time and temperature. Results showed that the expansible volume was 185. 7 mL/g when it was made by potassium permanganate and perchloric acid. Structure and morphology of natural flake graphite, expandable graphite and expanded graphite were analyzed by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The results showed that the intercalation was more complete when perchloric acid was used. Its bulkiness was better, and it was the most suitable for the preparation of composite phase change materials.