| Today, our country attached great importance to the economic construction and social construction, so the development of the materials industries became faster and faster. And the coating can protect the substance and prevent the matrix from wear, so more and more people paid attentions to the coating. At the same time, with the development of surface technology and engineering, the coating had become a kind of functional materials which gradually acted as an important branch in the industry. There, improving the hardness was important for the development of the coating preventing the matrix from wear, and was the basic demands for the functional coatings. Inorganic nano silica due to the high rigidity, high strength and surface effect, so in order to improve the hardness of the coating, people usually mixed nano silica with organic resin to prepare the organic-inorganic nano coating.In recent years, compared with thermal polymerization, the photopolymerization had the characteristics of low energy consumption and high reactivity, and sample can be cured when was exposed to the UV light for a short time (from a few seconds to a few minutes). So, in this work, UV polymerization technology had been used to prepare organic-inorganic nano coating.It has been reported that the organic and inorganic hybrid coatings were prepared by the sol-gel method with an acid to catalyze the inorganic precursor alkoxy silane hydrolysis and condensation. These reported acid often was small molecule acid such as hydrochloric acid and acetic acid, or the cationic photo-initiator which can produce super proton acid under UV irradiation. However, the small molecule acid may evaporate or corrode the coatings and the substrates, and the cationic photo-initiator (PAG) was expensive or low solubility in the formulation, therefore, the obtained coating properties can't meet the application in wide range of fields.So, the main research works of this paper were as follows:1. We developed a photopolyerizable acid to catalyze hydrolysis and condensation reaction of alkoxy silane in the UV-cured organic and inorganic hybrid coating. The photopolymerizible acid was synthesized by the esterification of hydroxyl ethyl acrylate and anhydride. The purity of product characterized by GC was higher than 98%. So the negative influence when the small molecule acid and the PAG were used as catalyst was avoided.2. Tetraethyl orthosilicate (TEOS) was used as precursor, KH570 was used as silane coupling agent, synthetic monomer was used as both catalyst and the organic monomer, and the 1173 was used as photo-initiator to prepare the coating. Subsequently, The hydrolysis and condensation reaction of alkoxy silane was proceeded in the condition with the humidity and temperature was about 80%?40? for different time. Adding different content of TEOS to regulate the hardness of the coatings. And the results showed that when the content of the TEOS was 20% in the system, the pencil hardness value of the coating was 3H and 6H, respectively, using different judgment standard. At the same time, the coating had excellent heat resistance and high transmittance. The results showed that the photopolymerizable acid could catalyze the hydrolysis of alkoxy silane in situ in the photopolymerization system.3. When the system containing 20% bisphenol A epoxy acrylate oligomer (6104) and 10% bi-functional monomer tripropylene glycol diacrylate (TPGDA), the prepared hybrid coating had high gloss, high transmittance, excellent water resistance and chemical stability. |
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