协效剂对膨胀阻燃聚丙烯基木塑复合材料的阻燃增效研究

赋予木塑复合材料(WPC)的阻燃性能成为近年来该领域国内外的研究热点之一。本文通过两轮正交试验,研究8种常见的协效剂对膨胀型阻燃剂(IFRs,m(聚磷酸铵,APP)∶m(季戊四醇,PER)=2∶1)的阻燃增效作用,筛选出具有显著协效作用的协效剂组MgO/EG(可膨胀石墨)/SiO_2,其组成为m(MgO)∶m(EG)∶m(SiO_2)=1∶5∶5,其与IFRs的最佳配比为m(IFRs)∶m(MgO/EG/SiO_2)=1∶0.18,得到性能良好的阻燃型聚丙烯基木塑复合材料。通过热重分析(TGA)和锥形量热分析(CONE)评价IFRs及协效剂组对聚丙烯(PP)基木塑复合材料(WPC)热稳定性能和阻燃性能的影响。结果表明,IFRs及MgO/EG/SiO_2的加入可以有效提高WPC的热稳定性,WPC/IFRs/MgO/EG/SiO_2600℃的残炭率达到22.42%。WPC/IFRs的热释放速率峰(PHRR)、总热释放量(THR)和总烟释放量(TSP)相比于WPC分别降低了21.9%、8.7%和22%。MgO/EG/SiO_2的加入可以进一步提高IFRs的阻燃效率,WPC/IFRs/MgO/EG/SiO_2的PHRR和THR相比于WPC分别降低了33.0%和13.8%。

Flame-retardant Synergistic Effect of Synergists on Intumescent Flame-retardant Wood Flour-Polypropylene Composites

Improving flame retardant properties of wood plastic composite material(WPC) has become one of the research hotspots of WPC in recent years. In this paper, the flame-retardant synergistic effects of eight kinds of synergists on intumescent flame retardants(IFRs, m(polyphosphate, APP):m(pentaerythritol, PER)=2:1) were studied by two rounds of orthogonal experiments. The synergist group MgO/EG(expandable graphite)/SiO₂with a significant synergistic flame retardant effect on the IFRs was obtained. The composition of MgO/EG/SiO₂is m(MgO):m(EG):m(SiO₂)=1:5:5, optimum proportion of m(IFRs):m(MgO/EG/SiO₂) is 1:0.18. The influence of IFRs and MgO/EG/SiO₂ on thermal stability and flame-retardant properties of polypropylene based wood-plastics composite(WPC) was evaluated by thermogravimetric analysis(TGA) and cone calorimetry analysis(CONE). The results show that adding IFRs and MgO/EG/SiO₂ to WPC can improve its thermal stability effectively, and the char residue of WPC/IFRs/MgO/EG/SiO₂ at 600 ℃ reaches to 22.42%. The peak heat release rate(PHRR), the total heat release(THR) and total smoke production release(TSP) of WPC/IFRs reduce by 19.0%, 8.7% and 22.1%, respectively, compared with WPC. MgO/EG/SiO₂ can further improve the flame retardant efficiency of IFRs, and the PHRR and THR of WPC/IFRs/MgO/EG/SiO₂ drop by 33.0% and 13.8%, respectively, compared with WPC.