Flame retardant mechanisms of red phosphorus and magnesium hydroxide in high impact polystyrene
Flame retardant mechanisms of red phosphorus and magnesium hydroxide in high impact polystyrene
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DOI：
10.1002/macp.200400255
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发表时间：
2004-11-03
影响因子：
2.5
通讯作者：
Schartel, B
中科院分区：
文献类型：
--
作者：
Braun, U;Schartel, B
通过综合分解研究和燃烧试验，研究了红磷、氢氧化镁和红磷与氢氧化镁复合阻燃高抗冲聚苯乙烯的阻燃机理。这项研究旨在阐明红磷在凝聚相和气相中作为烃类聚合物阻燃剂的先决条件和潜力。用热重-傅里叶变换红外光谱和质谱联用技术分别表征了热分解和热氧化分解过程、分解动力学和产物气体。用锥形量热计研究了不同外部热流密度下的燃烧行为，而可燃性由极限氧指数决定。利用XPS对燃烧残留物进行了分析。红磷减少了HIPS中的热释放，这是由于气相中的自由基被捕获所致。氢氧化镁通过散热机制、水的释放以及作为屏障的氧化镁层的形成来影响火灾行为。这两种阻燃剂在髋关节中的组合几乎导致了叠加。阻隔性能上的轻微协同作用是由于形成了磷酸镁，而在易燃性和气相作用方面则出现了轻微的反协同作用。后一种影响是由阻挡层导致的燃料速率降低控制的，而不是由凝聚相中的红磷氧化引起的。[图]HIPS在不同外部热流密度下的放热速率和总放热(点=70kW(.)M(-2)，虚线=50 kW(.)M(-2)，固体=30 kW(.)M(-2))。
The flame retardant mechanisms of red phosphorus, magnesium hydroxide and red phosphorus combined with magnesium hydroxide were studied in high impact polystyrene by means of comprehensive decomposition studies and combustion tests. The study is intended to illuminate prerequisites and the potential of red phosphorus as a fire retardant for hydrocarbon polymers in the condensed phase and in the gas phase. Thermal and thermo-oxidative decomposition, decomposition kinetics and the product gases evolved were characterized using thermogravimetry coupled with Fourier transform infrared spectroscopy and mass spectroscopy, respectively. Fire behaviour was investigated with a cone calorimeter using different external heat fluxes, whereas the flammability was determined by limited oxygen indices. The combustion residues were analysed using XPS. Red phosphorus reduced the heat release in HIPS due to radical trapping in the gas phase. Magnesium hydroxide influenced fire behaviour by heat sink mechanisms, release of water and the formation of a magnesia layer acting as a barrier. The combination of both flame retardants in HIPS nearly resulted in a superposition. A slight synergy in barrier characteristics was due to the formation of magnesium phosphate, whereas a slight anti-synergism occurred in flammability and in the gas phase action. The latter effect is controlled by a decreased fuel rate due to the barrier layer rather than by an initiation of red phosphorus oxidation in the condensed phase.[GRAPHICS]Heat release rate and total heat release at various external heat fluxes for HIPS (dotted = 70 kW (.) m(-2), dashed = 50 kW (.) m(-2), solid = 30 kW (.) m(-2)).