Ollivier-Lamarque Lucas, Livi Sébastien, Uchimoto Tetsuya, Mary Nicolas
ELyTMaX IRL3757, CNRS, Université de Lyon, INSA Lyon, Centrale Lyon, Université Claude Bernard Lyon 1, Tohoku University, Sendai 980-8577, Japan.
Institute of Fluid Science, Tohoku University, Sendai 980-8577, Japan.
Nanomaterials (Basel). 2022 Feb 15;12(4):651. doi: 10.3390/nano12040651.
Due to their high surface coverage, good adhesion to metal surfaces, and their excellent corrosion resistance, epoxy thermosets are widely used as protective coatings. However, anticorrosion protection of these coatings can be improved against water uptake and can be tuned by changing the chemical nature of the curing agents. In this work, a comparative study has been performed on the water uptake of an epoxy-amine based on bisphenol A diglycidyl ether (DGEBA) cured with an aliphatic amine and the same epoxy initiated with a phosphonium ionic liquid (IL). Thus, the epoxy networks were immersed in saline water solution in a controlled temperature environment. Gravimetric and electric impedance measurements were carried out for a maximum of 3 months. Results were analyzed in order to assess the water diffusion coefficients and water saturation limits. Two models, the Brasher-Kingsbury and a novel mixing rule, were applied on permittivity values. Results highlighted that epoxy-ionic liquid systems are less sensitive to water uptake than conventional epoxy-amine networks. Due to their higher hydrophobic properties the water diffusion coefficient of epoxy-ionic liquid systems are two times less compared to epoxy-amine samples and the water saturation limit is more than four times less. The analysis also shows that the novel mixing rule model proposed here is prone to better estimate the water uptake with accuracy from electrical impedance measurements.
由于具有高表面覆盖率、对金属表面的良好附着力以及出色的耐腐蚀性，环氧热固性材料被广泛用作防护涂层。然而，这些涂层的防腐蚀保护可通过防止吸水来改善，并且可以通过改变固化剂的化学性质进行调整。在这项工作中，对基于双酚A二缩水甘油醚（DGEBA）并用脂肪胺固化的环氧胺与用鏻离子液体（IL）引发的相同环氧树脂的吸水性进行了对比研究。因此，将环氧网络置于可控温度环境的盐水溶液中。进行了长达3个月的重量法和电阻抗测量。对结果进行分析以评估水扩散系数和水饱和极限。将两种模型，即布拉舍-金斯伯里模型和一种新的混合规则，应用于介电常数数值。结果表明，环氧-离子液体体系相比传统环氧-胺网络对吸水的敏感度更低。由于其更高的疏水性能，环氧-离子液体体系的水扩散系数比环氧-胺样品低两倍，水饱和极限则低四倍多。分析还表明，这里提出的新混合规则模型更易于通过电阻抗测量准确估计吸水率。
