过渡金属氧化物对木粉/PVC复合材料燃烧性能的影响

Effects of Transition Metal Oxides on the Combustion Properties of Wood-Flour/Polyvinyl Chloride Composites

用锥形量热仪(CONE)和热重分析法(TGA)研究金属氧化物CuO、La2O3和TiO2对木粉/PVC复合材料(WF-PVC)燃烧性能的影响。结果表明,这3种过渡金属氧化物的加入对WF-PVC均有阻燃作用。其中,CuO使热释放速率(HRR)和总热释放量(THR)降低较多,阻燃效果明显;加入金属氧化物使WF-PVC的烟释放速率(SPR)和总烟释放量(TSP)都有所降低,其中,CuO在有焰燃烧阶段烟释放量最低,抑烟效果最好。这3种氧化物都能增加成炭量。结合热重分析的结果,3种金属氧化物对WF-PVC的热降解影响是不同的。PVC和木粉之间存在相互作用,PVC显著促进了木粉的热降解,木粉的加入推迟了PVC的降解,明显提高了PVC体系的成炭量;WF-PVC的热降解行为,具有更多的PVC降解的特征。

The effects of transition metal oxides on the combustion properties of wood-flour/polyvinyl chloride （WF-PVC） composites were studied by cone calorimeter（CONE） and thermogravimetry analysis（TGA）. The effects of transition metal oxides on the fire-retardant and smoke-suppressant properties of WF-PVC composites were discussed. It was found that the addition of transition metal oxides such as CuO, La2 O3 and TiO2 to WF-PVC improved the fire-retardant performance of the composites, while compared to the other two metal oxides, better fire-retardant properties was observed in CuO treated composite which had much lower heat release rate （HRR） and total heat release （THR）. All these metal oxides promoted the yield of char residue, and the fire-retardant mechanism of the metal oxides was considered to be the condensed phase mechanism based on the analysis of effective heat of combustion （EHC） and HRR. smoke production rate （SPR） and total smoke release（TSP） of the composites was decreased as a result of the addition of the transition metal oxides, especially CuO, which was more effective than the others in the flaming phase. TGA results showed that CuO, La2O3 and TiO2 have different effects on the process of thermal degradation and decomposition of PVC/wood-flour compositions. At high temperature PVC and wood-flour interacted each other in the system of WF-PVC where PVC accelerated the degradation of wood flour while the yield of char resides was improved in the presence of wood-four. The thermal degradation characteristics of WF-PVC composites more resembled PVC than wood flour.