Wood has limited fire-retardant properties but this can be improved by using coatings with sustainable and cost-effective flame retardants. For this purpose, lignin is a potential candidate due to its highly aromatic structure and low cost. However, its structure should be modified to achieve good fire behaviour. Thus, phosphorus was incorporated into kraft lignin and the compounds obtained were used for the synthesis of two types of wood coatings: Polyurethanes and Polyacrylates. Phosphorus nuclear magnetic resonance was used to characterize the modified lignin, together with elemental analysis. The incorporation of lignin into the polymers was confirmed by infrared spectroscopy and gel content measurements. The effectiveness of the phosphorus-containing lignin intermediates as bio-based flame retardants was measured by thermogravimetric analysis (TGA), pyrolysis combustion flow calorimetry (PCFC) and cone calorimetry. According to the results, phosphorylated lignin increased the residue and decreased the total heat release of the polyurethane and acrylic coatings. In addition, slight improvements in fire resistance were observed in wood panels coated with acrylic, while no changes were observed in wood coated with polyurethane.

中文翻译：

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含磷木质素中间体作为反应性生物基阻燃剂，用于聚氨酯和丙烯酸木材涂料


木材的阻燃性能有限，但可以通过使用具有可持续且经济高效的阻燃剂的涂料来改善。为此，木质素因其高度芳香结构和低成本而成为潜在的候选者。然而，应修改其结构以实现良好的防火性能。因此，磷被掺入硫酸盐木质素中，所得化合物用于合成两种类型的木器涂料：聚氨酯和聚丙烯酸酯。使用磷核磁共振以及元素分析来表征改性木质素。通过红外光谱和凝胶含量测量证实木质素掺入聚合物中。通过热重分析（TGA）、热解燃烧流动量热法（PCFC）和锥形量热法测量了含磷木质素中间体作为生物基阻燃剂的有效性。结果表明，磷酸化木质素增加了聚氨酯和丙烯酸涂料的残留量并降低了总放热量。此外，涂有丙烯酸的木板的耐火性略有改善，而涂有聚氨酯的木材则没有观察到任何变化。