Zikeli Florian, Dominici Franco, Rallini Marco, Serna-Loaiza Sebastian, Wukovits Walter, Friedl Anton, Harasek Michael, Torre Luigi, Puglia Debora
Civil and Environmental Engineering Department, UdR INSTM, University of Perugia, Strada di Pentima 4, 05100 Terni, Italy.
Research Unit of Thermal Process Engineering and Simulation, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Getreidemarkt 9/166, 1060 Vienna, Austria.
Polymers (Basel). 2025 Aug 26;17(17):2308. doi: 10.3390/polym17172308.
Starch and lignin are promising biopolymers for the production of biodegradable biocomposite materials. The possibility of processing starch into thermoplastic materials qualifies it as a starting material for the preparation of thermoplastic packaging films, and the combination with lignin can even out some inherent weak points of starch, such as moisture and water sensitivity, and can add additional features like antioxidant activity. Lignins from herbaceous biomass carry building blocks that are not found in wood lignins and are known for their bioactivity, such as -coumaric acid or ferulic acid. In this work, a protocol was developed to initially prepare hybrids of wheat starch granules and lignin nanoparticles, which were then plasticized using glycerol in an extrusion process to produce thin films. The lignin-containing thermoplastic starch films showed higher Young's moduli and less elongation at break compared to neat thermoplastic starch films, while tensile strength remained at the level of the neat films. Thermal stability was slightly increased by lignin addition, and oxygen transmission rates were low for lignin contents as low as 1 wt%. The hydrophobicity of the lignin-containing films increased strongly, and they showed an elevated antioxidant activity over several hours, which was also maintained after 24 h. The preparation of hybrid wheat starch lignin particles was successfully tested for the extrusion of thermoplastic starch films with improved thermomechanical properties, decreased water sensitivity, and prolonged antioxidant activity.
淀粉和木质素是用于生产可生物降解生物复合材料的很有前景的生物聚合物。将淀粉加工成热塑性材料的可能性使其成为制备热塑性包装薄膜的起始材料，并且与木质素结合可以弥补淀粉一些固有的弱点，如对水分和水的敏感性，还可以增加额外的特性，如抗氧化活性。草本生物质中的木质素含有木材木质素中不存在的结构单元，并且以其生物活性而闻名，如对香豆酸或阿魏酸。在这项工作中，开发了一种方案，首先制备小麦淀粉颗粒和木质素纳米颗粒的混合物，然后在挤出过程中使用甘油进行增塑以生产薄膜。与纯热塑性淀粉薄膜相比，含木质素的热塑性淀粉薄膜显示出更高的杨氏模量和更低的断裂伸长率，而拉伸强度保持在纯薄膜的水平。添加木质素后热稳定性略有提高，对于低至1 wt%的木质素含量，氧气透过率较低。含木质素薄膜的疏水性大幅增加，并且它们在数小时内显示出增强的抗氧化活性，在24小时后仍能保持。成功测试了混合小麦淀粉木质素颗粒用于挤出具有改善的热机械性能、降低的水敏感性和延长的抗氧化活性的热塑性淀粉薄膜。
