Abstract A novel lignin-based flame retardant (LMD) is synthesized in this work via the in-situ reactions of lignin, diphenylmethane diisocyanate (MDI), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Flame-retardant polyurethane (FLPU) is prepared by the co-curing of LMD and prepolymer synthesized by lignin, MDI, and polyether polyol 204. Polyethylene glycol (PEG) 2000 is also added to adjust the flexibility of the lignin-based polyurethane (LPU). The limiting oxygen index (LOI) value of the FLPU gradually increases with the LMD content and can reach 29.9% for F30-L20-L15-80PU (L20MD content is 30% in L15-80PU), exhibiting excellent flame-retardant properties. The hardness of the FLPU for the optimized formulation is 2H, the adhesion is 0, and the flexibility is 2 mm. And the impact resistance is greater than 100 cm/1000 g. These outstanding properties illustrate the LMD is excellent flame retardants and reinforcing materials for LPU. The interface can be strengthened by the co-curing between the LMD and the LPU prepolymer.

中文翻译：

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一种新型含磷木质素基阻燃剂及其在聚氨酯中的应用

摘要 本工作通过木质素、二苯基甲烷二异氰酸酯 (MDI) 和 9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物 (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) 的原位反应合成了一种新型木质素基阻燃剂 (LMD)。 DOPO)。阻燃聚氨酯（FLPU）是由LMD与木质素、MDI、聚醚多元醇204合成的预聚体共固化制备的，还加入聚乙二醇（PEG）2000来调节木质素基聚氨酯（LPU）的柔韧性）。FLPU的极限氧指数（LOI）值随着LMD含量的增加而逐渐增加，F30-L20-L15-80PU可达29.9%（L15-80PU中L20MD含量为30%），表现出优异的阻燃性能。优化配方的FLPU硬度为2H，附着力为0，柔韧性为2mm。并且抗冲击性大于100 cm/1000 g。这些突出的性能说明LMD是LPU的优良阻燃剂和增强材料。LMD 和 LPU 预聚物之间的共固化可以加强界面。