膨胀石墨阻燃碱木质素聚氨酯泡沫的制备及其性能

通过对精制后的碱木质素进行羟甲基化改性,利用改性后的碱木质素部分代替聚醚多元醇,利用一步发泡法制备碱木质素基聚氨酯泡沫材料,之后将膨胀石墨(EG)作为阻燃剂添加到碱木质素基聚氨酯泡沫材料制备出阻燃型生物质聚氨酯泡沫,通过极限氧指数(LOI)测试分析研究了阻燃型生物质聚氨酯泡沫材料的阻燃性能。通过借助热重分析(TGA)、锥形量热测试(CONE)和扫描电子显微镜(SEM)测试,分析研究了材料的热降解行为和成炭性能、燃烧行为和充分燃烧后残炭的表面形貌。分析结果表面,当羟甲基化后的碱木质素的添加量为聚醚多元醇的60%(质量分数)时,EG的添加量为30%(质量分数)时,制备出的阻燃型生物质聚氨酯泡沫的LOI值为30.1%,同时EG的加入降低了材料最大热降解速率,热释放速率和总热释放量,促进了材料的成炭,提高了材料的热稳定性,提高了材料的阻燃性能。

Preparation and properties of alkali lignin-based polyurethane foam with expanded graphite

The alkali lignin-based polyurethane foam material was preparedwith one-step foaming method by modifying the hydroxymethylated alkali ligninand using the modified alkali lignin portion instead of the polyether polyol. And then the expanded graphite was added as a flame retardant to the alkali lignin-based polyurethane foamto prepare flame-retardant biomass polyurethane foam. The flame retardant properties of the flame-retardant biomass polyurethane foam were studied by limiting oxygen index (LOI) test. The thermal degradation behavior and char forming properties,combustion behavior and surface shape of carbon residue after full combustion were analyzed by means of thermo gravimetric analysis (TGA),cone calorimetry (CONE) and scanning electron microscopy (SEM). The results show that the limiting oxygen index of the flame retardant alkali lignin-based polyurethane foam was 30.1%,when 60% amount of polyether glycol was replaced by the hydroxymethylated alkali ligninand the loading amount of EG was 30%. The addition of EG reduced the maximum thermal degradation rate,heat release rate and total heat release rate of the material. Additionally,EG could promote the degradation and charring of the PUF,thereby improving the flame retardant properties of the PUF.