Simultaneous strengthening and toughening lignin/cellulose nanofibril composite films: Effects from flexible hydrogen bonds
Simultaneous strengthening and toughening lignin/cellulose nanofibril composite films: Effects from flexible hydrogen bonds
复制标题
同时增强和增韧木质素/纤维素纳米原纤维复合膜：柔性氢键的影响
DOI：
10.1016/j.cej.2022.139770
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发表时间：
2022-10-23
影响因子：
15.1
通讯作者：
Yue, Fengxia
中科院分区：
文献类型：
--
作者：
Ou, Jinfen;Hu, Songnan;Yue, Fengxia
受天然木材中木质素-纤维素网络的启发，我们开发了一种使用具有不同含量的酚羟基（Ph-OH）基团的木质素纳米颗粒（LNP）作为增强剂来制备纤维素纳米原纤维（CNF）复合膜的策略。通过酚化和反溶剂沉淀法成功制备了分子量较低、Ph-OH含量较高、形貌均匀的可调控LNP。与无木质素的CNF和具有较低Ph-OH含量的CNF复合材料相比，与高Ph-OH含量（8.23 mmol/g）的酚化LNP混合的CNF表现出更高的拉伸强度（类似于190 MPa）、增加的韧性（类似于15 MJ/m（3））和增强的UV阻挡能力（类似于99%）。因此，木质素上的Ph-OH基团和CNF上的羟基之间的氢键对于提高复合膜的机械强度至关重要。通过将酚化LNP添加到聚乙烯醇中作为强化剂，发现类似的增强的机械性能。这项研究提供了新的见解生产木质素增强纤维素复合膜的紫外线屏蔽，热稳定性和生物降解性。
Inspired by the lignin-cellulose network in natural wood, we developed a strategy to produce cellulose nanofibril (CNF) composite films using lignin nanoparticles (LNPs) with varied contents of phenolic hydroxyl (Ph-OH) groups as a reinforcing agent. Regulated LNPs with lower molecular weight, higher Ph-OH content, and uniform morphology were successfully prepared by phenolation and anti-solvent precipitation. CNFs mixed with phenolated LNPs of high Ph-OH content (8.23 mmol/g) exhibited a higher tensile strength (similar to 190 MPa), increased toughness (similar to 15 MJ/m(3)), and enhanced UV-blocking ability (similar to 99 %) compared to lignin-free CNFs and CNF composites with lower Ph-OH content. Thus, hydrogen bonds between Ph-OH groups on lignin and hydroxyl groups on CNFs are vital for enhancing the mechanical strength of composite films. Similar enhanced mechanical properties were found by adding phenolated LNPs into polyvinyl alcohol as a fortifier. This study provides novel insights into producing lignin-reinforced cellulose composite films with UV shielding, thermal stability, and biodegradability.