硬脂酸改性聚乙烯醇/纳米纤维素复合阻隔涂料的制备

目的 为了以安全环保的方式提高聚乙烯醇(PVA)阻水阻气性，制备高阻隔PVA涂料，提高PVA的性能与应用范围。方法 在聚乙烯醇中填充纳米纤维素(Cellulose Nanofiber，CNF)，并在此基础上添加硬脂酸进行耐水改性，探究对阻隔性能的影响，利用傅里叶红外光谱，X射线衍射，氧气、水蒸气透过率测试仪对其进行结构性能表征。结果 硬脂酸与PVA的酯化反应可以提高涂层的耐水性，PVA与CNF间能产生氢键，提高涂层结晶性能与阻隔性能，适量的硬脂酸的加入未降低CNF的结晶度，只降低了PVA的结晶性能，硬脂酸添加量为16%时涂层水蒸气透过率达到最低2.2 g/(m².d)，氧气透过率达到1.3 cm³/(m².d)。结论 利用CNF填充与硬脂酸酯化协同改性制备的PVA阻隔涂料具有较高的阻隔性能，使其在阻隔涂层方面具有广阔的应用前景。

Preparation of Stearic Acid Modified Polyvinyl Alcohol/Nanocellulose Composite Barrier Coatings

The work aims to improve the water and gas barrier properties of polyvinyl alcohol (PVA) in a safe and environmentally friendly manner, prepare a high barrier PVA coating and improve the performance and application range of PVA. Polyvinyl alcohol and cellulose nanofiber were blended. On this basis, stearic acid was added to conduct water resistance modification to explore its effect on the barrier performance. The structure and properties were characterized by Fourier infrared spectroscopy, XRD, oxygen and water vapor transmission tester. The results showed that the esterification reaction of stearic acid and PVA could improve the water resistance of the coating, and the hydrogen bond could be produced between PVA and CNF to improve the crystallinity and barrier property of the coating. The addition of appropriate stearic acid did not reduce the crystallinity of CNF, but only reduced the crystallinity of PVA. When the amount of stearic acid was 16%, the water vapor transmission of the coating reached the lowest 2.2 g/(m2.d) and the oxygen permeability reached 1.3 cm3/(m2.d). PVA barrier coating prepared by CNF blending and stearic acid esterifying has high barrier property, which makes it have broad application prospects in barrier coatings.