Abstract Hydrophobicity and anti-aging are two key features being sought in coating industry in light of their great importance in the development of self-cleaning materials for outdoor applications. The current study reports a nano-SiO2/fluorinated polyacrylate polyurethane (SiO2-FPEAU) composite coating that shows both good hydrophobicity and good anti-aging properties. Nano-SiO2 was first modified with γ-methacryloxypropyltrimethoxysilane (Kh570) to be well dispersed in fluorinated and hydroxyl acrylate monomers, where from copolymerization was carried out to form a nano-SiO2/ fluorinated polyacrylate composite resin (SiO2-FPEA). Cured with an isocyanate prepolymer (N3390) at room temperature, the SiO2-FPEA was cross-linked into the polyacrylate polyurethane (SiO2-FPEAU) composite coating. Numerous nano-SiO2 particles were observed on the film forming a surface nano-roughness, which was most likely driven by the surface self-segregation of surrounding fluorinated polymer chains. The nano-rough structure together with the fluorine enrichment on the film surface gave the composite coating a water contact angle of 116°. Moreover, the surface coverage of silica layer and the cross-linking structure in polyurethane greatly enhanced the anti-aging properties of the composite coating as demonstrated by less than 30 % of gloss loss after an artificial UV irradiation for 720 h. Besides, both chemical resistance and mechanical properties of the composite coating were improved thanks to the synergistic effect of the fluorine segments, the cross-linking in polyurethane and the nano-SiO2 particles. These findings indicated that the composite coating could be a very attractive solution for many practical areas, especially for outdoor applications.

中文翻译：

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纳米SiO2/氟化聚丙烯酸酯聚氨酯疏水复合涂层的制备及紫外老化

摘要 疏水性和抗老化性是涂料行业正在寻求的两个关键特性，因为它们在开发用于户外应用的自清洁材料中具有重要意义。目前的研究报告了一种纳米 SiO2/氟化聚丙烯酸酯聚氨酯 (SiO2-FPEAU) 复合涂层，它显示出良好的疏水性和良好的抗老化性能。纳米SiO2首先用γ-甲基丙烯酰氧基丙基三甲氧基硅烷（Kh570）改性，使其分散在含氟和羟基丙烯酸酯单体中，然后共聚形成纳米SiO2/含氟聚丙烯酸酯复合树脂（SiO2-FPEA）。在室温下用异氰酸酯预聚物 (N3390) 固化，SiO2-FPEA 交联成聚丙烯酸酯聚氨酯 (SiO2-FPEAU) 复合涂层。在薄膜上观察到许多纳米 SiO2 颗粒，形成表面纳米粗糙度，这很可能是由周围氟化聚合物链的表面自分离驱动的。纳米粗糙结构加上薄膜表面的富氟使复合涂层的水接触角为116°。此外，二氧化硅层的表面覆盖和聚氨酯中的交联结构大大增强了复合涂层的抗老化性能，在人工紫外线照射 720 小时后光泽损失小于 30%。此外，由于氟链段、聚氨酯中的交联和纳米二氧化硅颗粒的协同作用，复合涂层的耐化学性和机械性能均得到改善。