酸性熔盐水合物解聚木质素及其改性酚醛泡沫的性能研究（英文）

Properties of Phenolic Foam Modified by Lignin Depolymerized in Molten Salt Hydrate

利用无机离子液体(酸性熔盐水合物)实现了木质素的有效降解,并将其应用到改性酚醛泡沫的研究中。研究表明:木质素可被有效降解,重均相对分子质量从3 900降为1 600,分散系数也明显降低,从4.10降为1.78,从而可提高木质素改性产品的稳定性和重现性。另外,木质素解聚后,酚羟基含量大大提高,从而可以增强木质素的反应活性,也为提高木质素的利用度奠定了基础。通过解聚木质素改性酚醛泡沫的研究发现:木质素的取代量为30%时,木质素酚醛泡沫总体性能较好,其压缩强度为235 kPa,氧指数为38.1%,导热系数0.028 W/(m·K),属难燃型高效保温材料。

In this paper,lignin was effectively depolymerized by using inorganic ionic liquid(acidic molten salt hydrate)and applied in the research of modified phenolic foam.The results showed that lignin could be effectively degraded,the relative weight average molecular weight(M w)decreased from 3 900 to 1 600,and the polymer dispersity index(PDI)expressed by M w/M n also decreased from 4.10 to 1.78 markly which will lead to improvement of the stability and reproducibility in the lignin modified products.In addition,the phenolic hydroxyl content was greatly increased after lignin depolymerization,which can enhance the reactivity of lignin and lay a foundation for improving the utilization of lignin.Moreover,phenolic foam modified by 30%depolymerized lignin exhibited a good property with a compressive strength of 235 kPa,the limited oxygen index 38.1%and the coefficient of thermal conductivity 0.028 W/(m·K).These showed that the product might be non-combustible and efficient insulation materials.