MgO-微胶囊红磷/高抗冲聚苯乙烯复合材料的阻燃性能

通过熔融混合方法把MgO和（或）微胶囊红磷（MRP）加入高抗冲聚苯乙烯（HIPS）基体中制备了一系列不同组成的MgO-MRP/HIPS复合材料。采用极限氧指数（LOI）、垂直燃烧（UL-94）、锥形量热分析、TGA、SEM、XRD、FTIR等方法研究了复合材料的阻燃性能。结果表明，MgO和MRP单独使用时对HIPS的阻燃作用较小，但是当二者以适当比例共同使用时对HIPS有明显的协同阻燃作用。当MgO∶MRP∶HIPS的质量比为35∶15∶100时，复合材料的LOI为24.7%，UL-94级别达到V-0级，热释放速率和总热释放量显著降低，表现出良好的阻燃性能。MgO-MRP/HIPS复合材料在无氧条件下热分解时，MgO、MRP与HIPS之间无相互作用。但是，在空气中热分解或燃烧时，MgO和MRP均能够促进HIPS成炭。MgO-MRP/HIPS复合材料燃烧时能够在材料表面生成连续致密的炭层，起到防火屏障作用，提高材料的阻燃性能，燃烧残余物主要由结晶性MgO和含磷的无定形碳组成。此外，MgO-MRP/HIPS复合材料燃烧时MRP在气相也起到了一定的阻燃作用。

Flame retardancy of MgO-microencapsulated red phosphorus/high impact polystyrene composite

MgO and (or) microencapsulated red phosphorus (MRP) were incorporated into high impact polystyrene (HIPS) matrix by melt-compounding and a series of MgO-MRP/HIPS composites were prepared. The flame retardancy of MgO-MRP/HIPS composites was investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetry, TGA, SEM, XRD and FTIR. The results indicate that either MgO or MRP has slight flame retardant effect on HIPS when they are used alone, but there is obvious synergism between MgO and MRP on the flame retardancy of HIPS when they are combined at a proper mass ratio. When the mass ratio of MgO:MRP:HIPS is 35:15:100, the LOI of the MgO-MRP/HIPS composite is 24.7% and the UL-94 vertical burning rating of the composite can reach V-0. Both heat release rate and total heat release of composite are decreased noticeably. The composite with this composition exhibits excellent flame retardancy. There is no interaction among HIPS, MgO and MRP at high temperature in anaerobic condition. However, both MgO and MRP can promote charring when the polymer is degraded or burned in air. A continuous and compact charred residue layer can be produced on the surface of the MgO-MRP/HIPS composite, which acts as a barrier against fire and gives rise to increased flame retardancy. The burnt residue of the MgO-MRP/HIPS composite consists of crystalline MgO and phosphorus-containing amorphous black char. In addition, MRP also plays a flame retardant role in the gas phase during combustion of the composite.