Zhao Yadong, Troedsson Christofer, Bouquet Jean-Marie, Thompson Eric M, Zheng Bin, Wang Miao
School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China.
Ocean TuniCell AS, P.O. Box 12, 5868 Blomsterdalen, Norway.
Polymers (Basel). 2021 Dec 12;13(24):4346. doi: 10.3390/polym13244346.
Bio-based composite films have been widely studied as potential substitutes for conventional plastics in food packaging. The aim of this study was to develop multifunctional composite films by introducing cellulose nanofibers (CNF) and lignin into starch-based films. Instead of costly and complicated chemical modification or covalent coupling, this study optimized the performance of the composite films by simply tuning the formulation. We found that starch films were mechanically reinforced by CNF, with lignin dispersing as nanoparticles embedded in the matrix. The newly built-up hydrogen bonding between these three components improves the integration of the films, while the introduction of CNF and lignin improved the thermal stability of the starch-based films. Lignin, as a functional additive, improved hydrophobicity and blocked UV transmission. The inherent barrier property of CNF and the dense starch matrix provided the composite films with good gas barrier properties. The prepared flexible films were optically transparent, and exhibited UV blocking ability, good oxygen-barrier properties, high hydrophobicity, appreciable mechanical strength and good thermal stability. These characteristics indicate potential utilization as a green alternative to synthetic plastics especially for food packaging applications.
生物基复合薄膜作为食品包装中传统塑料的潜在替代品已得到广泛研究。本研究的目的是通过将纤维素纳米纤维（CNF）和木质素引入淀粉基薄膜来开发多功能复合薄膜。本研究并非采用昂贵且复杂的化学改性或共价偶联方法，而是通过简单调整配方来优化复合薄膜的性能。我们发现，淀粉薄膜通过CNF进行了机械增强，木质素以纳米颗粒的形式分散在基质中。这三种成分之间新形成的氢键改善了薄膜的整体性，而CNF和木质素的引入提高了淀粉基薄膜的热稳定性。木质素作为一种功能添加剂，提高了疏水性并阻隔了紫外线透过。CNF的固有阻隔性能和致密的淀粉基质赋予了复合薄膜良好的气体阻隔性能。制备的柔性薄膜具有光学透明性，表现出紫外线阻隔能力、良好的氧气阻隔性能、高疏水性、可观的机械强度和良好的热稳定性。这些特性表明其有潜力作为合成塑料的绿色替代品，特别是在食品包装应用方面。
