Lignin, a renewable biopolymer recovered from the chemical processing of woody biomass, has potential to enhance the mechanical properties of epoxy resins with the added benefit of reduced contents of non-renewable petroleum-based polymers. Lignin-based epoxy resins were prepared by employing a carboxylated lignin as a co-hardener using a “one-pot” method. The effect of lignin content and preparation method on mechanical properties, apparent morphology, and thermodynamic properties of the resulting epoxy resins were then studied. The results showed that elongation at break increased from 2.2 to 5.7%, and flexural strength increased from 23.3 to 101 MPa, with the addition of lignin up to 20 wt%. The highest increase in tensile strength was obtained for the lignin-based resin having a lignin content of 10 wt%. The incorporation of carboxylated lignin at an appropriate amount demonstrated simultaneous reinforcing and toughening effects on the epoxy resin, which can be attributed to the rigid and highly-branched structure of lignin.

木质素是一种从木质生物质的化学加工过程中回收的可再生生物聚合物，具有增强环氧树脂机械性能的潜力，并具有减少不可再生石油基聚合物含量的额外好处。通过使用“一锅法”将羧化木质素用作共硬化剂来制备木质素基环氧树脂。然后研究了木质素含量和制备方法对所得环氧树脂的机械性能，表观形态和热力学性能的影响。结果表明，当添加木质素至多20wt％时，断裂伸长率从2.2增加到5.7％，弯曲强度从23.3增加到101MPa。对于木质素含量为10wt％的木质素基树脂，拉伸强度的增加最大。