基于多层涂布工艺的高阻隔透明纸基材料的制备与性能

通过生物基可降解材料制造阻隔性包装的应用越来越受到人们的关注。然而,现有的技术仍较难同时实现纸基包装材料的高氧气阻隔性和水蒸气阻隔性。本研究以自制透明纸作为基底,采用天然高分子材料(淀粉、瓜尔胶)及环保水性防水剂为涂布层,通过涂布工艺制备了兼具高阻氧和阻水蒸气性能的透明纸基材料。结果表明,不同涂层之间充分发挥各自的阻隔作用,降低了外界水蒸气在纸基材料表面的吸附作用,同时增加了水分子和氧气分子在纸张内部的扩散难度;制得的透明纸基材料氧气透过率最低为2.46 cm3/(m2·day·0.1 MPa),水蒸气透过率仅为107.09 g/(m2·day),相比于未涂布的透明纸分别下降了92%和94%。同时,有防水层的透明纸基材料的纸与纸板表面吸水量(Cobb)值均小于1 g/m2,接触角大于90°,呈现出良好的疏水性和抗水特性。本文的制备工艺简便、制造成本较低、材料性能可控,有望在替塑包装中得到应用。 

Preparation and performance of high-barrier transparent paper-based materials via multi-coating technology

Recently, barrier packaging products made from biodegradable materials have attracted wide attention. However, most reported methods are still difficult to achieve both high oxygen barrier and water vapor resistance in paper-based packaging. In this study, high-barrier transparent paper-based materials was prepared based on coating technology, where homemade transparent paper served as a substrate, while the natural biomass materials (starch and guar gum) and environmental-friendly waterborne resin functioned as coatings. The results show that the barrier effect between different coatings is fully utilized, which reduces the adsorption of external water vapor on the surface of paper-based materials, and increases the difficulty of diffusion of water molecules and oxygen molecules inside the paper. The oxygen transmission rate and water vapor transmission rate of our resulting transparent paper-based materials are low to 2.46 cm3/(m2·day·0.1 MPa) and 107.09 g/(m2·day), respectively, which show a significant reduction of 92% and 94% compared to the uncoated transparent paper. Meanwhile, the surface water absorption of paper and board (Cobb) values of transparent paper-based materials with waterproof layer are less than 1 g/m2, and the contact angles are greater than 90°, showing good hydrophobicity and water resisting property. In short, we provided a simple and low-cost technical route to manufacture performance-adjustable paper, suggesting a great potential to achieve industrialization and partially replace plastic packaging.