摘要：采用化学共沉淀的方法,在相同的工艺条件下,固定Mg²⁺的浓度,通过改变Al³⁺的量,分别制备Mg与Al的物质的量比为5∶1、4∶1、3∶1、2∶1、1∶1的复合粉体和单一的氢氧化镁与氢氧化铝,通过X射线衍射、透射电镜、热重-差热分析、氮气吸附测定比表面积、堆密度等手段对合成样品进行表征。结果表明,合成样品为类水滑石结构Mg₆Al₂(OH)₁₈.4.5H₂O为主的混合物,呈现卷曲片状的形貌;Mg与Al的物质的量比为4∶1时制备的粉体为Mg(OH)₂和Mg₆Al₂(OH)₁₈.4.5H₂O的混合物,分散性好,分解温度高,是一种优良的阻燃剂。

关键词：超细粉体；阻燃剂；化学共沉淀

Abstract：The composite powders of Mg and Al with molar ratios of 5∶1,4∶1,3∶1,2∶1,1∶1 as well as single magnesium hydroxide and aluminum hydroxide were prepared via chemical coprecipitation method under the same processing conditions by changing the amount of Al³⁺ with fixed concentration of Mg²⁺.The samples were characterized through the means of XRD,TEM,TG-DTA,N2adsorption test specific surface area and bulk density.The results indicate that the samples show the curly sheet morphology based on hydrotalcite structure with Mg₆Al₂(OH)_18.4.5H₂O as the main content.The powders prepared at the condition that Mg and Al with molar ratio of 4∶1 are mixtures of Mg(OH)₂and Mg₆Al₂(OH)₁₈.4.5H₂O,which have good dispersion and high decomposition temperature,and are good flame retardants.

Keywords：superfine powder;flame retardant;chemical coprecipition