One-step synthesis of hydrophobic magnesium hydroxide nanoparticles and their application in flame-retardant polypropylene composites  

作　　者：Hongyan Shen Youzhi Liu 

机构地区：[1]Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, College of Chemical Engineering and Environment, North University of China

出　　处：《Chinese Journal of Chemical Engineering》2018年第10期2199-2205,共7页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(21376229);the Science and Technology of Shanxi Province(2015031019-5);the Natural Science Foundation for Young Scientists of Shanxi Province(2015021033)

摘　　要：Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.Hydrophobic magnesium hydroxide（MH） nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed（IS-RPB） reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties（e.g., high water contact angle of 112°）, and improved thermal stability of MH. The limiting oxygen index（LOI） further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.

关 键 词：Magnesium hydroxide SYNTHESIS POLYPROPYLENE Hydrophobic property Rotating packed bed 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业] TB33[一般工业技术—材料科学与工程]