偶联剂表面改性对膨胀阻燃聚丙烯性能的影响

采用硅烷偶联剂、钛酸酯偶联剂、铝钛、铝硅复合偶联剂对无卤膨胀型阻燃剂（IFR）进行表面改性，对比了表面改性前后IFR堆积密度和休止角的变化，研究了表面改性对IFR阻燃聚丙烯（PP）分散性能、力学性能及阻燃性能的影响，并采用锥形量热仪对比了表面改性前后IFR阻燃PP的燃烧行为。结果表明，4种表面改性剂中铝硅复合偶联剂的改性效果最优；可显著改善IFR在PP中的分散性，提高了PP的极限氧指数和UL 94阻燃级别，材料的断裂伸长率提升了200 %，冲击强度提升了50 %；还可抑制IFR的析出，材料燃烧时的热释放速率及总量、生烟速率及总量下降幅度达到30 %左右。

Effect of Surface Modification of Coupling Agents on Properties of Intumescent Flame retardant Polypropylene

A halogen free intumescent flame-retardant (IFR) was surface modified with the silane, titanate, and Al-Ti and Al-Si complex coupling agents. A comparative study of the effects of surface modification on the bulk density and the angle of repose of IFR was performed. The effects of surface modification on limited oxygen index, dispersion property, mechanical properties and flame retardancy of polypropylene (PP)/IFR composites were investigated. The combustion behaviors of the composites were evaluated by cone calorimeter before and after the surface modification of IFR. The results indicated that the Al-Si complex coupling agent had a high efficiency in surface modification. With the surface modification by use of the Al-Si complex coupling agent, the dispersion of IFR in PP matrix was enhanced greatly, and the flame retardancy and impact toughness of the composites were improved. Furthermore, the heat release rate, total heat release, smoke production rate, and total smoke production of the composites were reduced by 30 %.