Nuruddin Md, Chowdhury Reaz A, Szeto Ryan, Howarter John A, Erk Kendra A, Szczepanski Caroline R, Youngblood Jeffrey P
Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States.
School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
ACS Appl Mater Interfaces. 2021 Mar 17;13(10):12472-12482. doi: 10.1021/acsami.0c21525. Epub 2021 Mar 3.
CO and O gas permeability are paramount concerns in food packaging. Here, the permeability of cellulose nanocrystals (CNCs) and polyvinyl alcohol (PVA) coatings was explored as it relates to varied CNC content. Specifically, this work focuses on the role of PVA in rheology and barrier performance of the CNC films. Results show that shear-casted CNC films are transparent and have a high-order parameter, which is attributed to the shear-thinning behavior of the CNCs. The barrier performance of the CNC films improved because of the synergistic effect of having both alignment of CNCs and a lower free volume. The CNC-PVA films exhibited excellent barrier performance as compared to traditional engineered polymers, even much higher than high barrier ethylene-vinyl alcohol copolymer films. Furthermore, the moisture sensitivity of the films was greatly diminished with the addition of PVA. Overall, the results show applicability of CNC-PVA coating formulations for high barrier packaging applications.
一氧化碳和氧气的气体渗透性是食品包装中至关重要的问题。在此，研究了纤维素纳米晶体（CNC）和聚乙烯醇（PVA）涂层的渗透性与不同CNC含量之间的关系。具体而言，这项工作聚焦于PVA在CNC薄膜的流变学和阻隔性能方面的作用。结果表明，通过剪切浇铸法制备的CNC薄膜是透明的，并且具有较高的有序参数，这归因于CNC的剪切变稀行为。由于CNC的排列和较低的自由体积的协同作用，CNC薄膜的阻隔性能得到了改善。与传统工程聚合物相比，CNC-PVA薄膜表现出优异的阻隔性能，甚至比高阻隔乙烯-乙烯醇共聚物薄膜还要高得多。此外，添加PVA后，薄膜的湿度敏感性大大降低。总体而言，结果表明CNC-PVA涂料配方适用于高阻隔包装应用。
