Multifunctional polymers derived from renewable organic substances have received significant attention. In this work, the Diels–Alder “click” reaction was used to synthesize a renewable copolymer with the mechanical strength of cellulose nanocrystals (CNCs) and the natural antioxidant activity of lignin. Chemical structural analysis and molecular weight results confirmed that lignin was successfully attached to the CNCs. Phenolic hydroxyl groups were introduced into CNCs, resulting in good antioxidant activity with an IC₅₀ value of 1.49 mg/mL, although a slight decrease in the crystallinity index and thermal properties was observed. Additionally, carboxymethyl cellulose (CMC) films containing lignin-modified CNCs were prepared by solution casting. The lignin-modified CNCs endowed film with antioxidant activity and also contributed to increasing the tensile strength by 70%. This indicated that the lignin-modified CNCs with good antioxidant activities and mechanical strength have promising applications in multifunctional materials.

源自可再生有机物质的多功能聚合物受到了极大的关注。在这项工作中，Diels-Alder“点击”反应被用来合成一种具有纤维素纳米晶体（CNCs）机械强度和木质素天然抗氧化活性的可再生共聚物。化学结构分析和分子量结果证实木质素成功附着在 CNCs 上。将酚羟基引入 CNCs 中，产生良好的抗氧化活性，IC ₅₀值 1.49 mg/mL，尽管观察到结晶度指数和热性能略有下降。此外，通过溶液浇铸制备了含有木质素改性 CNCs 的羧甲基纤维素 (CMC) 薄膜。木质素改性的 CNCs 赋予薄膜抗氧化活性，并有助于将拉伸强度提高 70%。这表明具有良好抗氧化活性和机械强度的木质素改性CNCs在多功能材料中具有广阔的应用前景。