新型无机复合沥青阻燃剂的制备及其阻燃机理

Preparation of New Inorganic Composite Flame Retardant Modified Asphalt and Its Flame Retardant Mechanism

选取氢氧化镁、硼酸锌、聚磷酸铵作为原材料,以钛酸酯为表面改性材料,制备一种新型的无机复合阻燃剂。利用四因素三水平的正交方法制备不同阻燃剂复配组合,并结合极限氧指数、烟密度以及SBS阻燃沥青路用性能等试验,采用多指标加权综合分析方法评价不同复配条件下阻燃沥青的综合性能,以确定该阻燃剂的最佳配方。同时探讨该无机复合阻燃剂的阻燃机理。结果表明:采用钛酸酯处理液作为偶联剂处理阻燃剂中间体,钛酸酯用量范围为3.5%~4%。该阻燃剂的最佳配方为:氢氧化镁∶硼酸锌∶聚磷酸铵∶钛酸酯=1∶1∶1.65∶0.128。将无机复合阻燃剂掺入SBS改性沥青中,阻燃剂与SBS发生交联,SBS链段运动受阻,吸热量减小,提高了SBS改性沥青中轻组分的挥发温度,有效地减少了轻组分的挥发。在加热时阻燃剂会率先分解,分解过程中,吸收大量热量,释放难燃性气体,降低氧气浓度,从而达到阻燃的效果。

Hydroxide,zinc borate and ammonium polyphosphate were used as raw materials,and titanate was used as surface modification material to prepare a new type of inorganic composite flame retardant.The four-factor and three-level orthogonal method was used to prepare different flame retardant compounding combinations.Combined with the tests of limiting oxygen index,smoke density and SBS flame retardant asphalt,the multi-index weighted comprehensive analysis method was used to evaluate the flame retardant under different compounding conditions.The properties of the agent determined the optimum formulation of the flame retardant.At the same time,the thermal analysis mechanism of the new inorganic composite flame retardant was investigated.The results show that the titanate treatment solution is used as a coupling agent to treat the flame retardant intermediate,and the amount of titanate ranges from 3.5%to 4%.The best formula of the flame retardant is:magnesium hydroxide∶zinc borate∶ammonium polyphosphate∶titanate=1∶1∶1.65∶0.128.The inorganic composite flame retardant is incorporated into the SBS modified asphalt,the flame retardant cross-links with the SBS,the SBS segment movement is hindered,and the heat absorption is reduced.And improving the volatilization temperature of the light components in the SBS modified asphalt can effectively reduce the light component volatilization.The flame retardant will decompose first upon heating.During the decomposition process,a large amount of heat is absorbed,a flame retardant gas is released,and the oxygen concentration is lowered to achieve a flame retardant effect.