Guangdong Province Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
Guangdong Province Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
Int J Biol Macromol. 2024 Oct;277(Pt 3):134245. doi: 10.1016/j.ijbiomac.2024.134245. Epub 2024 Jul 28.
Polyvinyl alcohol (PVA) is a promising alternative to non-biodegradable flexible packaging materials, and nanocellulose is often used to enhance the properties of PVA films, but the composite films still have poor water resistance and barrier properties. To address this issue, iron ions (Fe) were introduced into PVA/cellulose nanofibrils (CNF) films, and Fe formed coordination bonds with carboxyl and hydroxyl groups on the surface of CNF and PVA chains. Therefore, constructing a strong coordination crosslinking network within the film and improving the interfacial interaction between PVA and CNF. The water resistance, mechanical and barrier properties of the crosslinked films were significantly improved. Compared with the un-crosslinked film, the oxygen transmission rate (OTR) was decreased by up to 67 %, and the water swelling ratio was significantly reduced from 1085 % to 352 %. The tensile strength of the film with 1.5 wt% Fe reached 41.93 MPa, which was 62 % higher than that of the un-crosslinked film. Furthermore, the composite film demonstrated good recyclability, almost recovering its original mechanical properties in two recycling tests. This simple and effective method for preparing water resistance and barrier films shows potential applications in flexible packaging areas.
聚乙烯醇（PVA）是一种很有前途的可替代不可生物降解的柔性包装材料的选择，而纳米纤维素通常被用于增强 PVA 薄膜的性能，但复合薄膜仍然具有较差的耐水性和阻隔性能。为了解决这个问题，将铁离子（Fe）引入到 PVA/纤维素纳米纤维（CNF）薄膜中，Fe 与 CNF 和 PVA 链表面的羧基和羟基形成配位键。因此，在薄膜内构建了一个强大的配位交联网络，并改善了 PVA 和 CNF 之间的界面相互作用。交联膜的耐水性、机械性能和阻隔性能得到了显著提高。与未交联的薄膜相比，氧气透过率（OTR）降低了高达 67%，水膨胀率从 1085%显著降低到 352%。添加 1.5wt%Fe 的薄膜的拉伸强度达到 41.93MPa，比未交联的薄膜提高了 62%。此外，该复合膜表现出良好的可回收性，在两次回收测试中几乎恢复了其原始的机械性能。这种简单有效的制备耐水和阻隔膜的方法在柔性包装领域具有潜在的应用前景。
