磷酸硼协效膨胀型阻燃剂对聚丙烯阻燃性能的研究

Research on Synergistic Effect of Boron Phosphate Intumescent Flame Retardant on Flame Retardancy of Polypropylene

在膨胀型阻燃剂(IFR)中添加不同比例的协效剂磷酸硼(BP)制备复合阻燃剂,将复合阻燃剂加入聚丙烯(PP)中,制备阻燃PP复合材料。通过垂直燃烧、极限氧指数测试、锥形量热测试、热重分析和力学性能测试对PP复合材料进行表征。结果表明:BP对IFR具有显著的协同阻燃效果。当添加2%BP和13%IFR时,PP/IFR/BP复合材料(样品4#)阻燃性能最佳,燃烧等级达到V-0,极限氧指数达到30.8%。样品4#的热释放速率峰值、平均热释放速率、总产烟量和总释放热与加入15%IFR的阻燃PP相比,分别降低19.51%、4.40%、34.00%和6.87%,700℃时样品4#的质量保留率增加50%。燃烧过程中,PP/IFR/BP复合材料的硼元素在凝聚相中催化IFR交联成炭,较未添加BP的复合材料,PP/IFR/BP炭层膨胀程度更高且更致密。BP协效剂的添加降低了阻燃剂的添加量,明显提升复合材料的力学性能。

The composite flame retardant was prepared by adding different proportions of synergist boron phosphate(BP)to the intumescent flame retardant(IFR).The composite flame retardant was added to polypropylene(PP) to prepare flame retardant PP composites.PP composites were characterized by vertical combustion,limiting oxygen index test,cone calorimeter test,thermogravimetric analysis and mechanical properties test.The results show that BP has significant synergistic flame retardant effect on IFR.When 2% BP and 13% IFR are added,PP/IFR/BP composite(sample 4#) has the best flame retardancy,the combustion grade reaches V-0,and the limiting oxygen index reaches 30.8%.The peak heat release rate,average heat release rate,total smoke production and total heat release of sample 4# are 19.51%,4.40%,34.00% and 6.87% lower than those of flame retardant PP with 15% IFR,respectively.The mass retention rate of sample4# is increased by 50% at 700 ℃.During the combustion process,the boron element of PP/IFR/BP composites catalyzes the crosslinking of IFR into carbon in the condensed phase.Compared with the composites without BP,the PP/IFR/BP carbon layer has a higher degree of expansion and is denser.The addition of BP synergist reduces the amount of flame retardant and significantly improves the mechanical properties of the composites.