Abstract:

In order to solve the problem of poor stability of short fluorocarbon chain foam, G-MNPs with different water contact angles were obtained by hydrophobic modification of magnesium oxide nanoparticles (MNPs) with stearic acid. The effects of hydrophobic modified MNPs on the performance and fire extinguishing performance of short fluorocarbon chain foam were studied. MNPs were modified by stearic acid for 60min, 90min, 120min and 150min, respectively. The surface morphology, particle size distribution, hydrophobicity, thermal stability and solution dispersion of the modified MNPs were tested. The effects of hydrophobic modification on foam stability, foaming ability, foam coarsening, fire extinguishing performance and burning resistance were studied. The results showed that when the hydrophobic modification time of stearic acid was 120min, the water contact angle of modified MNPs was the largest, reaching 138.4°. The surface roughness of the modified MNPs increased, the particle size increased, and the thermal stability was good at high temperature. Hydrophobic modification had little effect on the surface tension and viscosity of the foam solution. When the hydrophobic angle was 90.0°, the foaming performance, stability, fire extinguishing performance and burning resistance of the modified MNPs foam solution were the best.

Key words: stearic acid, hydrophobic modification, magnesium nano oxide particles(MNPs), short fluorocarbon chain foam, fire extinguishing performance

摘要：

为了解决短氟碳链泡沫稳定性差的缺点，采用硬脂酸对氧化镁纳米颗粒（MNPs）疏水改性得到不同水接触角的G-MNPs，研究疏水改性MNPs对短氟碳链泡沫性能和灭火性能的影响。采用硬脂酸对MNPs分别改性60min、90min、120min和150min，测试了G-MNPs表面形态、粒径分布、疏水性、热稳定性以及溶液分散度，研究了疏水改性对泡沫稳定性、发泡能力、泡沫粗化、灭火性能和抗烧性能等的影响。结果表明，硬脂酸疏水改性时间为120min时，改性MNPs水接触角最大，达到138.4°；G-MNPs表面形貌粗糙度增加，颗粒粒径增大，高温下热稳定性良好；疏水改性对泡沫溶液表面张力和黏度几乎没有影响；疏水角为90.0°时，G-MNPs泡沫溶液发泡性能、稳定性能、灭火性能、抗烧性能达到最佳。

关键词: 硬脂酸, 疏水改性, 纳米氧化镁, 短氟碳链泡沫, 灭火性能