木粉/聚乙烯阻燃复合材料的阻燃特性和力学性能研究

Flame retardant and mechanical properties of wood powders/PE composites

研究了聚磷酸铵阻燃剂和不同偶联剂对木粉/聚乙烯复合材料阻燃性能和力学性能的影响规律。实验结果表明:聚磷酸铵膨胀型阻燃剂添加量为30%时,氧指数从18.7%提高到26.5%,但力学性能有所下降。通过分别加入马来酸酐接枝PP、钛酸酯和硅烷偶联剂改善了复合材料的力学性能,并研究了偶联剂对复合材料阻燃性能的影响,钛酸酯添加量为2%时,阻燃型木粉/聚乙烯复合材料氧指数达到27.5%。热重分析表明阻燃剂聚磷酸铵对木粉/聚乙烯复合材料具有促进成炭,提高成炭量从而保护内部基材,降低了热降解速率,高温残炭量增加;特别是加入钛酸酯偶联剂后复合材料的成炭效果更加明显,热稳定性进一步增强,从而显著提高了材料的阻燃性。

The influence law of ammonium polyphosphate （APP） and coupling agents on the mechanical properties and flame retardant properties of wood powder/PE composites were studied by mechanical test and limited oxygen index （LOI） test. The experimental results show that the LOI of composites increased from 18.7% to 26.5% when the content of APP flame retardant was 30%, however the mechanical properties decreased. The maleic anhydride graft PP, titanate and silane coupling agent were used to improve mechanical properties of composites and it was implied that titanate and silane coupling agent can improve the mechanical properties of composites obviously. The limited oxygen index of wood powder/PE composites reached 27.5% when the content of titanate was 2%. Thermogravimetric analysis （TGA） shows that APP promoted charring and increased the amounts of char, thus protecting the inner matrix and increased the amount of residual char at higher temperature. The titanate coupling agent further increased the charring formed and rose the thermal stability, so obviously increased the flame retardant of composites.