Guo Yujie, Tian Dong, Shen Fei, Yang Gang, Long Lulu, He Jinsong, Song Chun, Zhang Jing, Zhu Ying, Huang Churui, Deng Shihuai
Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, Sichuan 610065, China.
Polymers (Basel). 2019 Sep 5;11(9):1455. doi: 10.3390/polym11091455.
Although recent work has shown natural lignin products are promising to fabricate various polymer based functional composites, high-value applications were challenged by their structural complexity and inhomogeneity. This work specially assessed the potential of four technical lignins for cellulose based functional films production. These four technical lignins were obtained by emerging pretreatment systems, i.e., lactic acid-betaine deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone (Soda/AQ) and the sodium salicylate hydrotrope, and their phenolic substructures were comparatively identified by prevalent P NMR technique. The influence of lignin chemical structure on the antioxidant potential and UV-shielding performance of the prepared cellulose/technical lignin composite films were assessed. Results showed severe organosolv and soda/AQ pretreatment produced technical lignins with higher total phenolic hydroxyl groups (3.37 and 3.23 mmol g-1 respectively), which also exhibited higher antioxidant activities. The composite films could effectively block the ultraviolet lights especially for UVB region (ultraviolet B, 280-315 nm) at only 5 wt.% lignin content. The contribution of lignin phenolic substructures to both antioxidant activity and UV-shielding property from high to low was syringyl > guaiacyl > -hydroxyphenyl phenolic hydroxyl groups. This work provided some useful information that could facilitate upstream lignin extraction or downstream value-added applications.
尽管最近的研究表明，天然木质素产品有望用于制造各种聚合物基功能复合材料，但其结构的复杂性和不均匀性给高价值应用带来了挑战。这项工作专门评估了四种工业木质素用于生产纤维素基功能薄膜的潜力。这四种工业木质素是通过新兴的预处理系统获得的，即乳酸-甜菜碱低共熔溶剂（DES）、乙醇有机溶剂法、苏打/蒽醌（Soda/AQ）和水杨酸钠助溶剂，并且通过常用的磷核磁共振技术对它们的酚类亚结构进行了比较鉴定。评估了木质素化学结构对制备的纤维素/工业木质素复合薄膜抗氧化潜力和紫外线屏蔽性能的影响。结果表明，严重的有机溶剂法和苏打/AQ预处理产生的工业木质素具有较高的总酚羟基含量（分别为3.37和3.23 mmol g-1），其抗氧化活性也较高。复合薄膜在木质素含量仅为5 wt.%时就能有效阻挡紫外线，尤其是对于UVB区域（紫外线B，280-315 nm）。木质素酚类亚结构对抗氧化活性和紫外线屏蔽性能的贡献从高到低依次为紫丁香基>愈创木基>对羟基苯基酚羟基。这项工作提供了一些有用的信息，有助于上游木质素提取或下游增值应用。
