A^(l3+)交联的聚丙烯酸钠凝胶防灭火特性

Fire prevention and extinguishing characteristics of Al 3+cross-linked sodium polyacrylate gel

为解决传统矿用防灭火凝胶保水性能差、受热易分解等问题,基于高分子材料聚丙烯酸钠易与高价态金属离子发生分子交联从而凝胶化的特性,研制出一种耐高温、高保水的新型Al^(3+)聚合物防灭火凝胶。从热稳定性、阻化效果及官能团3个方面分析Al^(3+)聚合物凝胶的阻化机理,首先利用恒温干燥箱和热重试验测试凝胶在不同温度条件下失水率、质量及特征温度点变化情况;其次利用程序升温气相色谱法对升温过程中的气相产物进行检测,根据检测结果进行气体阻化率计算和活化能氧化动力学分析;最后利用红外光谱仪研究聚合物凝胶对煤分子中官能团的影响。结果表明:Al^(3+)与聚丙烯酸钠交联形成的三维网络结构使凝胶具有良好的热稳定性,在150℃恒温条件下加热12 h,最大失水率为42.9%,凝胶阻化煤样其特征温度点均出现不同程度的延后;凝胶阻化后的煤样CO气体的生成量大幅度减少,最大CO阻化率为76.76%;凝胶能通过提高煤氧反应所需的活化能以及降低参与煤氧反应官能团的含量来降低煤的自燃倾向性,活化能最大增幅为14.6%。研究结果以期为高分子材料在煤火灾害治理方面的应用及发展提供一定的参考。

In order to solve the problems of poor water retention performance and easy decomposition by heat of traditional mining fire extinguishing gel.A new type of Al^(3+)polymer fire extinguishing gel with high temperature resistance and high water retention has been developed.Based on the property that the polymer material sodium polyacrylate is easy to cross-link molecules with high valence metal ions and thus gelation.The blocking mechanism of Al^(3+)polymer gels is analyzed in terms of thermal stability,blocking effect and functional groups.Firstly,the constant temperature drying oven and thermogravimetric test were utilized to test the water loss rate,mass and characteristic temperature point changes of the gel under different temperature conditions.Secondly,the gas-phase products of the warming process were detected using programmed warming gas chromatography,and gas resistivity calculations and activation energy oxidation kinetics analyses were performed based on the results.Finally,the infrared spectroscopy was used to examine the effect of polymer gels on functional groups in coal molecules.The results show that:Al^(3+)and sodium polyacrylate crosslinked to form a three-dimensional network structure so that the gel has good thermal stability,the maximum water loss rate is 42.9%at 150℃under constant temperature heating for 12 h,and the gel blocking coal samples of its characteristics of the temperature point are delayed in different degrees.The generation of CO gas in the coal samples after gel blocking was greatly reduced,and the maximum CO blocking rate was 76.76%.Gel can reduce the propensity of coal to spontaneous combustion by increasing the activation energy required for the coal oxygenation reaction and by decreasing the content of functional groups involved in the coal oxygenation reaction,with a maximum increase in activation energy of 14.6%.The results could provide a reference for the application and development of polymer materials in coal fire disaster management.