采用高强度微波对木材进行预处理提高其渗透性能,通过加压浸渍将不同质量比的硅源前驱物和聚磷酸铵(APP)混合液引入到木材的孔道中,经过后续的缩合和干燥处理,在木材孔道中原位生成了SiO_2/APP复合凝胶。采用电子扫描电镜(SEM)和锥形量热仪等测试手段,考察了该复合凝胶在木材中形成、燃烧过程中的协同阻燃、烟气转化和抗流失性能的影响。测试结果表明,木材中原位生成的SiO_2/APP复合凝胶具有优异的阻燃和抑烟性能。其中,硅源前驱物与APP溶液质量比为1∶8处理试样点燃155s后熄灭,且其总热释放量下降了93.6%,总烟释放量和CO平均释放量分别降低了61.6%,53.9%;质量比为1∶9的试样在实验条件下30min点不燃,表现出优异的阻燃性。通过比较阻燃处理木材在抗流失实验前后的阻燃性能,结果表明该复合凝胶可改善阻燃木材的抗流失性,从而提高木材阻燃时效。
Firstly, wood was treated by high-strength microwave in order to improve its permeability. Then, thedifferent mass ratio of silica source precursor and ammonium polyphosphate (APP) mixture solution was intro-duced into the wood through impregnating method under pressure, after that the SiO2/APP composites gel for-mation in-situ the wood after subsequently condensation and drying processing. The morphology, synergisticeffect on fire-retardance and smoke behavior of the SiO2/APP composite were investigated by electronic scan-ning microscope (SEM), cone calorimeter and other techniques in present work. The results show that theSiO2/APP composite gel has excellent flame retardance and smoke suppression performance. As a result, siliconsource and APP precursor mass ratio of 1 : 8 post-treatment samples ignited 155 s then extinguished. It is clear-ly seen that a reduction of total heat release (THR) to 93.7%, the total smoke production (TSP) and the meanof CO yield (m-COY) were decreased to 61.6% and 53.9%, respectively. The mass ratio of 1 : 9 specimens un-der the experimental conditions for 30 rain is non-combustible, exists excellent flame retardance. By comparingthe fire parameters of specimens before and after leaching, it is found that the gel composites can prevent theloss of APP, which can extend the period of wood flame retardance.