摘要
以硫酸镁为原料,氢氧化钠为沉淀剂,加入适量硬脂酸钠(NaSt)和聚乙二醇(PEG2000)作为表面活性剂,采用液相沉淀法制备高纯超细阻燃型氢氧化镁粉体.考察沉淀方式、反应物配比、反应温度、搅拌速率、反应时间、表面活性剂配比、表面活性剂用量和洗涤方式等对氢氧化镁粉体粒径的影响.测试了产物形貌、晶相结构、粒径及粒径分布、纯度、分散效果和润湿性.结果表明:制备超细氢氧化镁的适宜的工艺条件包括,沉淀方式为双向沉淀,n(NaOH)∶n(MgSO4)=2.5∶1.0,反应温度为60℃,搅拌速率为400 r/min,反应时间为50 min,NaSt/PEG2000的配比为4∶1、添加量为4 g/mol MgSO4,洗涤方式为纯水洗涤3次.所得的氢氧化镁表面呈疏水性,接触角达123.50°,分散性好,纯度高达99.50%,平均粒径为3.83 µm,粒度分布均匀并呈六方片状晶体.样品白度、纯度和粒径满足阻燃剂用氢氧化镁指标.
Abstract
High purity ultrafine flame retardant magnesium hydroxide powder was prepared by the liquid phase precipitation method using magnesium sulfate as raw material,sodium hydroxide as precipitant,and sodium stearate(NaSt)and polyethylene glycol(PEG2000)as surfactants.The effects of precipitation mode,reactant ratio,reaction temperature,stirring rate,reaction time,surfactant ratio,surfactant dosage,and washing method on the particle size of magnesium hydroxide powder were investigated.The product morphology,crystalline phase structure,particle size and its distribution,purity,dispersion effect,and wettability were tested.The results show that the suitable process conditions for the preparation of ultrafine magnesium hydroxide are as follows:the precipitation method is two-way precipitation,n(NaOH)∶n(MgSO4)= 2.5∶1.0,the reaction temperature is 60℃,the stirring rate is 400 r/min,the reaction time is 50 min,the ratio of NaSt/PEG2000 is 4∶1,the addition amount is 4 g/mol MgSO4,and the washing method is pure water washing for three times.The surface of the obtained magnesium hydroxide is hydrophobic,the contact angle is up to 123.50°,the dispersion is good,the purity is as high as 99.50%,the average particle size is 3.83 μm,and the particle size distribution is uniform and hexagonal lamellar crystal.The whiteness,purity and particle size of the sample met the magnesium hydroxide index for flame retardant.
基金项目
湖北省高等学校优秀中青年科技创新团队项目(T2021006)
武汉市知识创新专项曙光计划(2022020801020356)
武汉工程大学大学生校长基金(XZJJ2023052)
湖北省科技计划重点研发专项(2023BCB076)
国家科技期刊平台
NSTL
万方数据