Loesch-Zhang Amelia, Cordt Cynthia, Geissler Andreas, Biesalski Markus
Macromolecular and Paper Chemistry, Technical University Darmstadt, Alarich-Weiss-Str. 8, 64287 Darmstadt, Germany.
Papiertechnische Stiftung (PTS), Pirnaer Str. 37, 01809 Heidenau, Germany.
Polymers (Basel). 2022 Apr 27;14(9):1773. doi: 10.3390/polym14091773.
Hydrophobic coatings are of utmost importance for many applications of paper-based materials. However, to date, most coating methods demand vast amounts of chemicals and solvents. Frequently, fossil-based coating materials are being used and multiple derivatization reactions are often required to obtain desired performances. In this work, we present a solvent-free paper-coating process, where olive oil as the main biogenic component is being used to obtain a hydrophobic barrier on paper. UV-induced thiol-ene photocrosslinking of olive oil was pursued in a solvent-free state at a wavelength of 254 nm without addition of photoinitiator. Optimum reaction conditions were determined in advance using oleic acid as a model compound. Paper coatings based on olive oil crosslinked by thiol-ene reaction reach water contact angles of up to 120°. By means of Fourier transform infrared spectroscopy and differential scanning calorimetry, a successful reaction and the formation of a polymer network within the coating can be proven. These results show that click-chemistry strategies can be used to achieve hydrophobic polymeric paper coatings while keeping the amount of non-biobased chemicals and reaction steps at a minimum.
疏水涂层对于纸质材料的许多应用至关重要。然而，迄今为止，大多数涂层方法需要大量的化学品和溶剂。通常，使用基于化石的涂层材料，并且经常需要多次衍生化反应才能获得所需的性能。在这项工作中，我们提出了一种无溶剂的纸张涂层工艺，其中使用橄榄油作为主要生物成分在纸张上获得疏水屏障。在无溶剂状态下，于254nm波长进行紫外线诱导的橄榄油硫醇-烯光交联反应，且不添加光引发剂。预先使用油酸作为模型化合物确定了最佳反应条件。通过硫醇-烯反应交联的基于橄榄油的纸张涂层的水接触角可达120°。借助傅里叶变换红外光谱和差示扫描量热法，可以证明涂层内反应成功且形成了聚合物网络。这些结果表明，点击化学策略可用于实现疏水性聚合物纸张涂层，同时将非生物基化学品的用量和反应步骤降至最低。
