Pellis Giulia, Caldera Fabrizio, Trotta Francesco, Biazioli de Oliveira Thais, Rizzi Paola, Poli Tommaso, Scalarone Dominique
Department of Chemistry, University of Torino, Via Pietro Giuria 7, 10125 Torino, Italy.
Molecules. 2024 Dec 3;29(23):5702. doi: 10.3390/molecules29235702.
Outdoor bronze statues are constantly exposed to weather conditions and reactive compounds in the atmosphere that can interact with their surfaces. To avoid these interactions, a commonly used method is the application of coatings with corrosion inhibitors. However, a significant limitation of these inhibitors is their gradual loss over time. In this study, we aimed to improve the durability of 5-ethyl-1,3,4-thiadiazol-2-amine (AEDTA), the inhibitor chosen to formulate new acrylic coatings for outdoor bronzes. Methyl-β-cyclodextrin (Me-β-CD) was selected to host the inhibitor due to the capability of cyclodextrins to form complexes incorporating small organic molecules. The complexes of Me-β-CD and AEDTA were prepared and the inclusion of AEDTA was proved by Fourier-transform infrared spectroscopy, X-ray diffraction and nuclear magnetic resonance spectroscopy. Then, acrylic coatings were prepared at different concentrations of the Me-β-CD/AEDTA system. They were thermally aged and monitored every 24 h. To evaluate the volatilization of the corrosion inhibitor, solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) and thermal desorption-GC/MS (TD-GC/MS) analyses were performed during the first 72 h. The results were compared to those of pure AEDTA films and Incralac. The outcomes showed that Me-β-CD/AEDTA complexes are promising candidates for developing coatings with improved stability and longer retention of AEDTA.
户外青铜雕像不断暴露于天气条件以及大气中的活性化合物中，这些物质会与雕像表面发生相互作用。为避免这些相互作用，一种常用方法是涂覆含有缓蚀剂的涂层。然而，这些缓蚀剂的一个显著局限性是它们会随着时间逐渐流失。在本研究中，我们旨在提高5-乙基-1,3,4-噻二唑-2-胺（AEDTA）的耐久性，该缓蚀剂被选用于配制新型户外青铜丙烯酸涂层。由于环糊精能够形成包含小分子有机化合物的络合物，因此选择甲基-β-环糊精（Me-β-CD）来容纳缓蚀剂。制备了Me-β-CD与AEDTA的络合物，并通过傅里叶变换红外光谱、X射线衍射和核磁共振光谱证实了AEDTA的包合。然后，以不同浓度的Me-β-CD/AEDTA体系制备丙烯酸涂层。对它们进行热老化处理，并每24小时监测一次。为评估缓蚀剂的挥发情况，在最初的72小时内进行了固相微萃取-气相色谱/质谱联用（SPME-GC/MS）和热脱附-气相色谱/质谱联用（TD-GC/MS）分析。将结果与纯AEDTA薄膜和Inralac的结果进行比较。结果表明，Me-β-CD/AEDTA络合物有望用于开发具有更高稳定性和更长AEDTA保留时间的涂层。
