次磷酸铝添加量对碱木质素基聚氨酯 泡沫阻燃性能的影响

利用精制后的碱木质素部分代替聚醚多元醇制备碱木质素基聚氨酯泡沫材料(PUF/木质素)。将次磷酸铝(AHP)作为阻燃剂添加到材料中制备PUF/木质素/AHP材料。通过极限氧指数(LOI)测试PUF/木质素/AHP材料的阻燃性能，通过热重分析(TG)研究了材料的热降解行为和成炭性能，通过锥形量热(CONE)测试和扫描电子显微镜(SEM)分别研究了PUF/木质素/AHP材料的燃烧行为和残炭的表面形貌。结果表明：当碱木质素添加量为聚醚多元醇的5%、AHP的添加量为30%时，PUF/5%木质素/30%AHP材料的LOI值达到了25.6%，同时降低了材料的热分解速率和热释放量，促进了材料的成炭。当AHP受热分解时，产生的PO自由基会捕捉材料燃烧时产生的氢氧自由基，从而抑制燃烧反应，同时产生磷酸铝和焦磷酸铝，形成致密的炭层阻隔物质和能量的传递，阻止材料进一步燃烧，从而提高材料的阻燃性能。

Effect of Aluminum Hypophosphite Addition on Flame Retardancy of Alkali Lignin Based Polyurethane Foam

Alkali lignin-based polyurethane foam(PUF/lignin) was prepared by substituting a part of the polyether polyol with the refined alkali lignin. The PUF/lignin/AHP material was prepared by adding aluminum hypophosphite(AHP) as flame retardant to alkali lignin-based polyurethane foam material. The flame retardant properties of PUF/lignin/AHP materials were tested by limiting oxygen index(LOI), and the thermal degradation behavior and char forming properties of the materials were investigated by thermogravimetric analysis(TG). Cone calorimetry(CONE) and scanning electron microscopy(SEM) were used to study the combustion behavior of PUF/lignin/AHP materials and the surface morphology of char residue. The test results showed that when the addition amount of alkali lignin was 5% of polyether polyol and the amount of AHP was 30%, the LOI value of PUF/5%lignin/30% AHP material reached 25.6%, and the thermal decomposition rate and total heat release of the material were lowered, and the char formation of the material was promoted. When AHP was decomposed by heat, the generated PO radicals captured the hydroxyl radicals generated during the combustion of the material, thereby suppressed the combustion reaction. At the same time, aluminum phosphate and aluminum pyrophosphate were produced to form dense carbon layer barrier substance and energy transfer, which prevented the material from further burning and improved the flame retardancy of the material.