卤水制备阻燃用六角片状氢氧化镁研究

Study on Preparation of Hexagonal Flake Magnesium Hydroxide for Flame Retardant Using Brine

氢氧化镁作为绿色无卤阻燃剂,在复合材料阻燃领域备受关注。阻燃用氢氧化镁,除纯度、白度等常规指标外,要求氢氧化镁呈规则的六角片状,以保证在制备复合材料时的分散性。文章以卤水为原料,分别以氢氧化钠、氨水和三乙胺为沉淀剂,利用反应器制备耦合水热反应器制备了氢氧化镁。结果表明,以氢氧化钠为沉淀剂制备的氢氧化镁样品团聚严重,而以氨水和三乙胺制备的氢氧化镁分散性相对良好,呈不规则片状。耦合水热反应,釜底为有机溶剂抑制了(001)晶面的生长。釜底选用0.1 mol/L氢氧化钠可以制备六角片状氢氧化镁,样品白度、纯度和粒径满足阻燃用氢氧化镁指标。

Magnesium hydroxide,as a green halogen-free flame retardant,has attracted much attention in the field of composite flame retardant.Besides the conventional indexes such as purity and whiteness,magnesium hydroxide for flame retardance is required to be regular hexagonal flakes to ensure the dispersibility of the composite materials.In this article,using brine as raw material and sodium hydroxide,ammonia water and triethylamine as precipitants,magnesium hydroxide was prepared by using a reactor to prepare a coupled with hydrothermal reactor.The results showed that the magnesium hydroxide samples prepared with sodium hydroxide as precipitant had serious agglomeration,while the magnesium hydroxide prepared with ammonia water and triethylamine had relatively good dispersibility and were irregular flakes.Coupled with the hydrothermal reaction,the organic solvent at the bottom of the autoclave inhibited the growth of(001) crystal planes.Hexagonal flake magnesium hydroxide can be prepared by using 0.1 mol/L sodium hydroxide at the bottom of the kettle.The whiteness,purity and particle size of the sample meet the requirements of magnesium hydroxide for flame retardant.