Paper Surface Science Program, University of Maine, Orono, ME 04469, United States; Department of Chemical and Biomedical Engineering, University of Maine, Orono, ME 04469, United States.
Paper Surface Science Program, University of Maine, Orono, ME 04469, United States; Department of Chemistry, University of Maine, Orono, ME 04469, United States.
Carbohydr Polym. 2020 Dec 15;250:117001. doi: 10.1016/j.carbpol.2020.117001. Epub 2020 Aug 29.
Cellulose nanofibrils (CNF) coatings are excellent grease barriers for biodegradable packaging. However, barrier properties are moisture sensitive, so hydrophobic components such as latexes or polymers are needed to impart moisture resistance, but incompatibility leads to poor dispersion. In this work, CNF modified with norbornenes was reacted with natural rubber (NR) latex in water to improve dispersion, coating formation, and coating moisture resistance by creating hybrid particles. Mixtures and reacted samples were coated through filtration onto paper. The hybrid particles improved NR retention and drainage rate as compared to the CNF/latex mixture. Hybrid particle coatings showed more uniform NR dispersion as compared to the mixtures, which formed NR and CNF layers. NR addition to coatings increased the water contact angle, reduced water absorption, and decreased the water vapor transmission rate. All coatings passed a 12-kit grease test before folding and the mixtures formed a crack-resistant CNF layer on the surface.
纤维素纳米纤维（CNF）涂层是可生物降解包装的优秀油脂阻隔层。然而，阻隔性能对湿度敏感，因此需要使用疏水性成分（如胶乳或聚合物）来赋予耐湿性，但不相容性会导致分散不良。在这项工作中，用降冰片烯改性的 CNF 在水中与天然橡胶（NR）胶乳反应，通过形成杂化粒子来改善分散性、涂层形成和涂层耐湿性。混合物和反应样品通过过滤涂覆到纸上。与 CNF/胶乳混合物相比，杂化粒子提高了 NR 的保留率和排水率。与混合物相比，杂化粒子涂层显示出更均匀的 NR 分散，形成 NR 和 CNF 层。NR 的添加增加了水接触角，减少了吸水率，并降低了水蒸气透过率。所有涂层在折叠前都通过了 12 套件油脂测试，混合物在表面形成了耐裂纹的 CNF 层。
