聚乙烯薄膜防雾涂层的制备与性能研究

目的 制备一种新型环保、综合性能优异的高透明防雾涂层，解决生鲜食品的塑料包装薄膜极易发生雾化的问题。方法 通过溶液共混法将聚乙烯醇（Polyvinyl Alcohol,PVA）和海藻酸钠（Sodium Alginate,SA）混合制备PVA-SA防雾涂料，并利用刮涂法将其涂覆于PE薄膜表面，以制备防雾涂层。测试分析涂层的组成，以及对薄膜防雾性能的影响，并使用分子动力学模拟软件分析水分子在不同界面的运动行为，探究PVA-SA涂层的防雾机理。结果 经过测试分析发现，采用质量分数为2.78%的PVA和0.84%的SA制备的涂层展现出最佳的防雾效果，且该涂层具有超亲水性，其水接触角低至7.8°，所制备涂覆膜的平均透光率高达93.2%，平均雾度仅为3.44%，该涂覆膜在热雾中表现出高透明度，且对奶油草莓具有良好的保鲜效果。在模拟分析中发现，水滴与涂层间的平均结合能为水滴与薄膜的结合能的57倍。结论 PVA-SA涂层具有高透明性，在不影响薄膜原有透明性的同时有助于增强薄膜的润湿性，可以对生鲜食品起到很好的保鲜作用。采用模拟分析剖析了亲水涂层的防雾机理，结果表明该涂层材料在保鲜包装薄膜的防雾功能化应...

Preparation and Properties of Anti-fogging Coatings for Polyethylene Packaging Films

The work aims to prepare an environment-friendly and highly transparent anti-fogging coating to address the easily fogging problem in plastic packaging films for fresh products. Polyvinyl alcohol (PVA) and sodium alginate (SA) were used to prepare the anti-fogging coating which was coated on the surface of polyethylene (PE) film via blade coating. The composition of the coating and its effect on the anti-fogging performance of the film were tested and analyzed, and the motion behavior of water molecules at different interfaces was analyzed by molecular dynamics simulation software to explore the anti-fogging mechanism of the PVA-SA coating. It was found that the optimized composition of the anti-fogging coating was 2.78% of PVA and 0.84% of SA, which was capable of endowing the PE film great anti-fogging performance and good hydrophilicity with the water contact angle as low as 7.8°. Moreover, the coated film exhibited good transparency with the transmittance as high as 93.2%. The average fog degree was only 3.44%. The coating film showed high transparency in hot fog and had a good preservation effect for Zhangji strawberries. The simulation indicated that the average bonding capacity between the water and the coating was 57 times that of the original film. These findings demonstrated that the proposed PVA-SA coating had a high transparency, helped to enhance the wettability of the PE film without sacrificing its original transparency, and played a good preservation effect on fresh food. The anti-fogging mechanism of the hydrophilic coating was analyzed by simulation. The result showed that the coating had great prospects in anti-fogging performance of packaging films for fresh products.