氢氧化镁/膨胀石墨复合材料的制备

Preparation and characterization of magnesium hydroxide/exfoliated-graphite composites

为改善膨胀石墨的阻燃性能,以天然鳞片石墨为原料、重铬酸钾为氧化剂、浓硫酸为插层剂制备可膨胀石墨,经原位滴定法得到氢氧化镁/膨胀石墨复合材料。用扫描电子显微镜和X射线衍射仪对样品进行微观形貌和物相分析。结果表明,所制备的膨胀石墨为蠕虫多孔结构,氢氧化镁为六方晶系,形貌为球形,平均粒径约为250 nm,且氢氧化镁纳米粒子成功负载于膨胀石墨的边缘和内壁。XRD表征显示,膨胀石墨的存在并未改变氢氧化镁的晶型结构。该研究可以为制备氢氧化镁/膨胀石墨复合型阻燃剂提供理论参考。

This paper attempts to improve the flame retardant properties of the expandable graphite. The improvement is realized by preparing expandable graphite using natural flake graphite as raw materi- als, sulfuric acid as the intercalating agent, and potassium dichromate as oxidant and applying high-tem- perature puffing technique; and ultimately preparing magnesium hydroxide/exfoliated-graphite composites using situ titration method. Characterizing the products by scanning electron microscopy （SEM） and X- ray powder diffraction（XRD） shows that exfoliated-graphite has a porous and worm-like structure; mag- nesium hydroxide occurs as a hexagonal system with a spherical morphology and an average particle size of 250 nm; magnesium hydroxide nanoparticles are successfully loaded on the edge of the exfoliated- graphite and the lining; and the existence of the expanded graphite affords no change in the crystal struc- ture of magnesium hydroxide. The research may provide a theoretical reference for the preparation of mag- nesium hydroxide/exfoliated-graphite flame retardant.