A simple and environmentally benign synthetic route to lignin-based epoxy resins is highly desirable. Alkali lignin and glyoxal are promising renewable and sustainable alternatives to phenol and formaldehyde, respectively. Their use is demonstrated to produce lignin-phenol-glyoxal novolac epoxy resins (LPG-NERs) through a simple one-pot synthesis. Flame retardancy of LPG-NERs was improved by functionalization with a N, S modified 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) material (termed DBS) obtained via nucleophilic reaction between DOPO and a N, S containing intermediate. FTIR and ¹H NMR analyses confirmed the successful fabrication of LPG-NERs and SBD. The introduction of lignin and SBD reduced crosslinking of the epoxy network, weakening mechanical properties, but conferred excellent flame retardancy (including vapor and condensed phases) as determined by LOI (34.5%), UL-94 (V-0 rating), and cone calorimetry tests (lower heat release and smoke production, and higher char formation). The SBD structure imparted a desirable vapor mechanism (blowing out phenomenon caused by the fire quenching effect of PO•/PO₂• radicals and dilution effect from non-condensable gases such as NH₃, N₂, SO₂), while lignin (a natural biochar precursor) in synergy with SBD imparted superior charring performance.

非常需要一种简单且环境友好的木质素基环氧树脂合成路线。碱木质素和乙二醛分别是苯酚和甲醛的有前途的可再生和可持续替代品。它们的用途已被证明可以通过简单的一锅法合成生产木质素-苯酚-乙二醛酚醛环氧树脂 (LPG-NER)。通过 DOPO 与 N 之间的亲核反应获得的 N, S 修饰的 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) 材料（称为 DBS）进行功能化，提高了 LPG-NER 的阻燃性，S含中间体。FTIR 和¹H NMR 分析证实了 LPG-NER 和 SBD 的成功制造。木质素和 SBD 的引入减少了环氧树脂网络的交联，削弱了机械性能，但赋予了优异的阻燃性（包括蒸气和凝聚相），由 LOI (34.5%)、UL-94（V-0 等级）和锥量热测试（较低的热量释放和烟雾产生，以及较高的炭形成）。SBD 结构赋予了理想的蒸汽机制（由 PO•/PO ₂ • 自由基的熄火效应和不可冷凝气体如 NH ₃、N ₂、SO _{2 的}稀释效应引起的吹出现象），而木质素（a天然生物炭前体）与 SBD 协同作用赋予了卓越的炭化性能。