氢氧化铝/蒙脱土复合阻燃沥青的制备与性能研究

Preparation and Properties of Flame-retardant Bitumen with Aluminium Trihydroxide/Montmorillonite

将氢氧化铝与蒙脱土复合用于制备阻燃沥青,通过氧指数评价了氢氧化铝/蒙脱土复合阻燃沥青的燃烧性能,采用X射线衍射表征了复合阻燃沥青燃烧前后蒙脱土的结构变化,探讨了氢氧化铝/蒙脱土复合对沥青的阻燃作用机理。结果表明,氢氧化铝与蒙脱土复合对沥青氧指数的提高显著大于单一氢氧化铝或蒙脱土,二者对沥青表现出良好的协同阻燃效应,10%氢氧化铝和10%钠基蒙脱土复合制备的阻燃沥青氧指数达到24%,与掺加25%氢氧化铝制备的阻燃沥青氧指数相当。蒙脱土和氢氧化铝同时加入沥青时,蒙脱土片层发生剥离,对沥青表现为气固相协同阻燃作用机理。

The flame-retardant bitumen was prepared with the mixture of aluminium trihydroxide and montmorillonite. The flammability of the flame-retardant bitumen with aluminium trihydroxide/montmorillonite was evaluated by the limiting oxygen index. The structural change of the montmorillonite before and after combustion of the flame-retardant bitumen was analyzed by the X-ray diffraction test in order to reveal the flame retardant mechanism. Results show that the mixture of aluminium trihydroxide and montmorillonite can increase the oxygen index of bitumen more significantly than the single aluminium trihydroxide or montmorillonite, which indicates that the aluminium trihydroxide and montmorillon- ite exhibit a synergetic effect on the flame retardancy of bitumen. The oxygen index of flame-retardant bitumen with 10% aluminium trihydroxide and 10G sodium-montmorillonite could reach to 24~//0, which is equal to that of flame-retardant bitumen with 25 G aluminium trihydroxide. The layers of montmorillonite are exfoliated when the montmorillonite and a- luminium trihydroxide are mixed with bitumen together. The mechanism of the flame-retardant bitumen with aluminium trihydroxide/montmorillonite can be ascribed to the synergetic effect of gas-solid phase flame retardancy.