Mg(OH)2-Al(OH)3-微胶囊红磷/高抗冲聚苯乙烯无卤阻燃复合材料

以氢氧化镁(MH)、氢氧化铝(ATH) 和微胶囊红磷(MRP) 为无卤阻燃剂, 高抗冲聚苯乙烯(HIPS) 树脂为聚合物基体, 通过熔融共混法制备了一系列不同组成的MH-ATH-MRP/HIPS复合材料。采用水平燃烧、垂直燃烧、氧指数、锥形量热分析、高温热分解实验等方法研究了复合材料的阻燃性能。结果表明, 阻燃剂用量相同时, 在HIPS基体中同时引入MH和ATH得到的复合材料比单独加入MH或ATH得到的复合材料具有更好的阻燃性能。当MH-ATH/HIPS的质量比为70:30:100时, 复合材料的水平燃烧级别达到FH-1级, 氧指数为25.2%, 但垂直燃烧无级别。在上述体系中加入极少量的MRP(占复合材料的质量分数为2.9%)就可使复合材料的火灾性能指数(FPI) 提高85%, 燃烧过程中热量释放和质量损失更慢、成炭能力明显增强, 垂直燃烧级别达到FV-0级。当MH-ATH-MRP/HIPS的质量比为21:9:12:100时, 复合材料的各项阻燃性能达到最佳, 可以大幅度减少阻燃剂的用量。MH、ATH和MRP对HIPS具有非常显著的协同阻燃作用。同时加入MH和ATH时不仅可以在更宽的温度范围内抑制HIPS的升温和分解, 而且能够在更宽的温度范围内相继释放出水蒸气稀释氧气和可燃气体的浓度, 从而起到协同阻燃作用。加入MRP后复合材料的成炭能力大大增强, 进一步改善了凝聚相阻燃的效果, 因此阻燃性能显著提高。

Halogen-free flame retardant Mg(OH)2 Al(OH)3 MRP/HIPS composites

Using magnesium hydroxide (MH), aluminum trihydrate (ATH) and microencapsulated red phosphorus (MRP) as halogen-free flame retardants and high impact polystyrene (HIPS) as polymer matrix, a series of MH-ATH-MRP/HIPS composites were prepared by melt-compounding the flame retardants and HIPS. The flame retardancy of the composites was investigated by means of horizontal burning, vertical burning, oxygen index, cone calorimetry and high temperature pyrolysis experiments. It is shown that the composite containing both MH and ATH exhibits better flame retardancy than its counterpart containing only MH or ATH at the same flame retardant contents. When the mass ratio of MH-ATH/HIPS is 70:30:100, the horizontal burning rating of the obtained composite can reach FH-1 and its oxygen index is 25.2%, but its vertical burning cannot meet any rating. The introduction of a tiny amount of MRP, whose mass fraction is 2.9% of the composite, to the above composite can make the fire performance index of the composite increase by 85% and slow the heat release and mass loss upon combustion. Meanwhile, the charring ability of the composite is enhanced considerably and the vertical burning reaches FV-0 rating. The composite displays optimal fire retardancy when the mass ratio of MH-ATH-MRP/HIPS is 21:9:12:100, thus reducing the loading of flame retardant remarkably. There is very prominent synergistic flame retardant effect among MH, ATH and MRP to HIPS. The coexistence of MH and ATH can not only suppress the temperature rise and pyrolysis of HIPS in a much wider temperature range, it can also release water vapor one after another in a much wider temperature range, which dilutes the concentrations of both oxygen and combustible gases. Thus, they have a synergistic effect in HIPS composites. The charring ability of the composite is enhanced appreciably after the introduction of MRP, which has further improved the effect of condensed phase flame retardation. Consequently, the fire retardancy of the composites is increased considerably.