PP/LGF复合材料的膨胀性阻燃与协效阻燃性能

采用膨胀型阻燃剂(IFR)及协效剂海泡石(SP)对长玻璃纤维增强聚丙烯(PP/LGF)复合材料进行阻燃,通过双螺杆挤出机制备了PP/LGF母粒,IFR母粒和SP母粒,然后将这3种母粒通过注塑机制备了PP/LGF/IFR/SP复合材料,通过极限氧指数(LOI)、垂直燃烧测试、锥形量热仪、热重分析、扫描电子显微镜、力学性能测试等表征PP/LGF各阻燃复合体系的性能。结果表明,当IFR质量分数为22%时,PP/LGF/IFR阻燃复合材料的LOI为28.8%,且垂直燃烧等级达到V–0级;锥形量热仪测试结果表明加入IFR及SP后阻燃复合体系的第一热释放速率峰值降低,而第二热释放速率峰消失;SP质量分数为1%,IFR质量分数为21%的PP/LGF/IFR/SP阻燃复合材料LOI为29.6%,垂直燃烧等级达到V–0级,热释放速率峰值和总热释放量得到有效降低,热稳定性最好,且燃烧时产生致密的炭层覆盖于玻璃纤维表面,同时加入1%SP后复合材料的力学性能下降幅度相对较小。

Intumescent Flame Retardant and Synergistic Effect of PP/LGF Composites

Intumescent flame retardant (IFR) and synergistic flame retardant sepiolite (SP) were used for flame-retardant long glass fibers reinforced polypropylene (PP/LGF) composites. The PP/LGF masterbatches,IFR masterbatches and SP masterbatches were prepared with twin screw extruder and they were blended into the injection molding machine for preparing PP/LGF/IFR/SP composites. The properties of PP/LGF,PP/LGF/IFR and PP/LGF/IFR/SP flame retardant composites were inverstigated by the limited oxygen index (LOI) and vertical burning tests,cone calorimeter test (CONE),thermal gravimetry,scanning electron microscope and mechanical properties tests. The results show that when the mass fraction of IFR is 22%,the LOI value of PP/LGF/IFR composite reaches 28.8%,and the vertical burning test reaches V-0 rate. The CONE results show that the values of the first pHRR decreases and the second pHRR almost vanishes with adding IFR and SP into PP/LGF composites. When the mass fraction of SP and IFR is 1% and 21% separately,the LOI value of PP/LGF/IFR/SP composite is 29.6%,vertical burning test reaches V-0 rate,pHRR and THR are decreased effectively,thermal stability is best,and when the composite is burned,the glass fibers surface is covered with dense carbon layer,what's more,the mechanical properties of the composite has relative less decrease.