AHP/碱木质素聚氨酯泡沫的阻燃性能

对精制后的碱木质素进行羟甲基化改性,再利用改性后的羟甲基化碱木质素部分替代聚醚多元醇,采用一步发泡法与聚合MDI制备了羟甲基化木质素基聚氨酯泡沫材料。将次磷酸铝(AHP)作为阻燃剂添加到泡沫中制备了阻燃碱木质素聚氨酯泡沫,通过极限氧指数(LOI)测试分析了羟甲基化木质素基阻燃聚氨酯泡沫的阻燃性能。利用热重分析(TG)和扫描电子显微镜(SEM)分别研究制得泡沫的热降解行为、成炭性能和残炭形貌。实验结果表明,当羟甲基化碱木质素替代聚醚多元醇的量为60%,次磷酸铝的添加量为30%时,碱木质素聚氨酯泡沫材料的极限氧指数(LOI)值达到了27.5%。因此,羟甲基化碱木质素和次磷酸铝使泡沫在燃烧时能更好的形成炭层,从而有效地隔绝空气,降低热传递,提高了材料的阻燃性能。

Flame Retardancy of AHP/Alkali Lignin Based Polyurethane Foam

The refined alkali lignin was modified by hydroxymethylation,and the modified hydroxymethylated alkali lignin was partly used to replace polyether polyols.The hydroxymethylated lignin based polyurethane foam was prepared by one-step foaming and polymerized MDI.Flame retardant alkali lignin polyurethane foam was prepared by adding aluminum hypophosphite(AHP)as flame retardant.The flame retardancy of hydroxymethylated lignin based flame retardant polyurethane foam was analyzed by limiting oxygen index(LOI)test.Thermogravimetric analysis(TG)and scanning electron microscopy(SEM)were used to study the thermal degradation behavior,charring performance and carbon residue morphology of the prepared foam.The experimental results showed that the limit oxygen index(LOI)value of alkali lignin polyurethane foam reached 27.5%when the amount of hydroxymethylated alkali lignin instead of polyether polyols was 60%and the dosage of aluminum hypophosphite was 30%.Because the introduction of hydroxymethylated alkali lignin and aluminum hypophosphite.The foam could better form carbon layer when burning,which could effectively isolate the air,reduced heat transfer and improved the flame retardancy of the material.