氢氧化铝阻燃剂粒径对沥青性能的影响

Effect of particle size of aluminium hydroxide flame retardant on properties of asphalt

采用1、6.5、25、45μm 4种粒径的氢氧化铝(ATH)制备改性沥青,通过氧指数和热重分析试验研究ATH粒径对沥青阻燃效果和热氧化分解温区的影响,结合针入度和软化点试验研究ATH粒径对沥青基本性能指标的影响。结果表明:在阻燃剂掺量为25%时,在1~45μm范围内,ATH的粒径越大,沥青的阻燃效果越好,其中45μmATH改性沥青的阻燃效果最好,可将沥青的氧指数值提升至28.5%;热重分析结果表明,1μmATH和45μmATH都将沥青的各阶段热氧化分解温区提前,且1μmATH改性沥青的第一个失重峰速率明显大于45μmATH改性沥青。同时,沥青针入度值随ATH粒径的增大呈下降趋势,软化点则无明显规律。

The modified asphalt was prepared by using aluminum hydroxide(ATH)with four particle sizes of 1μm,6.5μm,25μm,and 45μm.The influence of ATH particle size on the flame retardant effect and thermal oxidation decomposition temperature zone of asphalt is studied by limiting oxygen index and thermogravimetric analysis.The penetration and softening point tests are used to study the influence of ATH particle size on the basic performance indexes of asphalt.The results show that when the flame retardant content is 25%,in the range of 1~45μm,the larger the particle size of ATH,the better the flame retardant effect of the asphalt.Among them,the 45μmATH modified asphalt has the best flame retardant effect.The oxygen index value of asphalt can be increased to 28.5%;Thermogravimetric analysis results show that both 1μmATH and 45μmATH advance the thermal oxidation decomposition temperature zone of each stage of asphalt,and the first weight loss peak rate of 1μmATH modified asphalt is obviously greater than 45μmATH modified asphalt.At the same time,the penetration value of asphalt shows a downward trend with the increase of ATH particle size,and there is no obvious law of softening point.