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Transparent polysilicone coatings as protecting films for gold commemorative coins



Novel transparent organic silicone resin coatings were successfully prepared through the reaction between the alkoxy groups of methyltrimethoxy-silane (MTMS) and γ-aminopropyltriethoxysilane (APTES) and hydroxyl groups of hydroxyl terminated silicone oil (HTSO). The influences of different monomer feed mass ratio on the coating properties were investigated via measuring the hydrophobicity and hardness of coating films. The coating films were characterized with IR, UV, TG, scanning electron microscope (SEM), and automatic contact angle meter. Some properties of coating films, such as adhesion, impact resistance, and wear-resistance, were also evaluated. The results indicated that these coating films formed on the surfaces of gold commemorative coins possessed some good properties including high hydrophobicity, high water contact angles, high light transmittance, good heat-resistance, adhesion, hardness, and weatherability, etc. Moreover, the uniform, clear, transparent, and dense coating films did not cover the symphony surface patterns or affect the metallic luster. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011