School of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China.
School of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning 530004, China.
Int J Biol Macromol. 2023 Jun 15;240:124473. doi: 10.1016/j.ijbiomac.2023.124473. Epub 2023 Apr 16.
Chitosan (CS) is a natural biopolymer from crab shells known for its biocompatibility and biodegradability; however, CS films are extremely rigid, limiting their applications. In this study, CS composite films were prepared based on the selective dissolution of lignin by deep eutectic solvents (DES), and the toughening effect of this DES/lignin on a CS film substrate was examined, along with its corresponding mechanism. The addition of DES/lignin effectively increased the plasticity of the CS film, giving a maximum elongation at break of 62.6 % for the plasticized film, which is 12.5 times that of the CS film. Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses showed that molecules in the DES/lignin complex interacted with CS to break the hydrogen bonds between the CS molecules; simultaneously, each molecule recombined with the CS molecules via hydrogen bonding. Thus, the rigidity of the CS molecular chain was weakened to achieve a plasticized CS film, thereby demonstrating the ability of DES/regenerated lignin to improve the toughness of CS films, which provides a reference for modifying plasticity and could lead to the broader utilization of CS films.
壳聚糖（CS）是一种天然生物聚合物，来源于蟹壳，具有良好的生物相容性和生物降解性；然而，CS 薄膜的刚性极高，限制了其应用。本研究基于通过深共熔溶剂（DES）选择性溶解木质素，制备 CS 复合薄膜，并考察了该 DES/木质素对 CS 薄膜基底的增韧效果及其相应的机制。DES/木质素的添加有效提高了 CS 薄膜的塑性，使增塑薄膜的断裂伸长率达到 62.6%，是 CS 薄膜的 12.5 倍。傅里叶变换红外光谱和核磁共振分析表明，DES/木质素复合物中的分子与 CS 相互作用，打破 CS 分子间的氢键；同时，每个分子通过氢键与 CS 分子重新组合。因此，CS 分子链的刚性减弱，得到了增塑 CS 薄膜，证明了 DES/再生木质素提高 CS 薄膜韧性的能力，为改善塑性提供了参考，可能会导致 CS 薄膜更广泛的应用。
