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  UV-Curable Boron Containing Hybrid Coatings

  UV-Curable Boron Containing Hybrid Coatings. BOREN-2009-Ç0210. Y. Mülazim, M.V. Kahraman, N.K. Apohan, A. Bayülken ve A. Güngör (Project Budget 98.000 TL)

  A series of ultraviolet (UV)-curable, boron- containing hybrid coatings were prepared by an anhy- drous sol–gel technique from a mixture of an acrylated bisphenol A based epoxy resin, methacryloxymethyl trie- thoxysilane, and boric acid. The use of boric acid allowed the hydrolysis and condensation of hybrid silicon alkox- ides without the further addition of water or a catalyst. The chemical structure of the boron-containing hybrid coatings was characterized with Fourier transform infra- red, real-time infrared, and 29Si cross-polarization/magic- angle spinning NMR techniques. UV-curable coatings were applied to polycarbonate and Plexiglas substrates. The physical and mechanical properties of the UV-cured coatings (e.g., pendulum hardness, pencil hardness, contact angle, gel content, methyl ethyl ketone rubbing test, tensile test, abrasion resistance, chemical resistance, neutron absorption, and limiting oxygen index) were examined. The hybrid coatings showed a significant enhancement in their radiation-shielding properties. The thermal behavior of the coatings was also evaluated. It was observed that the thermal stability of the coatings mainly depended on their boron and silicate contents. The results of all analyses of the free films and coatings were examined. 10B containing organic–inorganic hybrid coat- ing material based on a UV-curable formulation was pre- pared via anhydrous sol–gel technique. UV curable coatings were applied on Plexiglas (PMMA) substrates. The molecular structure of the coating material was ana- lyzed by ATR-FTIR spectroscopy technique. The charac- terization of the UV-curable coating was evaluated by various techniques such as gel content, abrasion resistance, chemical resistance, pencil hardness, pendulum hardness, MEK rubbing test, contact angle, cross-cut test, gloss, transmittance test, neutron absorption, Limiting Oxygen Index and stress–strain tests. Hybrid coatings showed a signi?cant enhancement in radiation shielding properties. The thermal behavior of coatings was also evaluated. It is observed that the thermal stability of coatings mainly depends on their boron and silicate contents. Results of all analysis conducted on hybrid ?lms, and coatings were discussed.

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  Characterization of Hydrophobic Coatings

  Characterization of Hydrophobic Coatings. Marmara University BAPKO A TYPE Research Project. FEN-A-060510-0131 (Project Budget 40.000 TL)

  Modification and use of natural products have gained a lot of interest in recent years due to their environ- mental friendliness and their availability from different sources. In this study, (castor oil)-based photo-curable highly hydrophobic coatings were prepared and char- acterized. Castor oil was first modified with 3-isocya- natopropyltriethoxysilane and then hydrolyzed prior to the coating preparation. The resulting precursor was mixed with norbornyl acrylate and hexanediol diacry- late, and highly roughened hydrophobic coatings were prepared with the aid of fluorinated/nonfluorinated alkoxysilane coupling agents and hydrophobic fumed nanosilica particles. The coatings were applied on bor- ofloat glass. The addition of fluorine and nanosilica showed a significant impact on the properties of the coatings. As the fluorine and nanosilica contents were increased in the formulations, flame retardancy and the contact angle values of the coatings increased. The surface roughness of the coatings increased with the addition of hydrophobic fumed nanosilica particles. Also, the relation between the surface energy and the contact angle values of the coatings was investigated. Modification and use of natural products have gained a lot of interest in recent years due to their environmental friendliness and their availability from different sources. In this study castor oil based photo curable highly hydrophobic coatings were prepared and characterized. Castor oil (CO) was first modified with 3-isocyanato propyl triethoxy silane and then it was hydrolyzed prior to the coating preparation. The resulting precursor was mixed with norbornyl acrylate, hexane diol diacrylate and hydrophobic coatings were prepared with the aid of fluorinated and nonfluorinated alkoxy silane coupling agents. The addition of fluorine showed a significant impact on the properties of the coatings. As the fluorine content was increased in the formulations, flame retardancy and the contact angle values of the coatings increased. The highest amount of fluorine containing coating showed a contact angle of 119°. Then with the addition of nonfluorinated alkoxysilane compounds, a contact angle of 130° was reached. Also the effect of post-cure temperature on contact angle values was investigated. Thiol–ene photocurable highly hydrophobic and oleophobic coatings were prepared and characterized. Trimethylolpropane tris(3-mercaptopropionate) and triallyl 1,3,5-triazine-2,4,6(1H,3H,5H)-trione were used for the preparation of the base formulation. Highly hydrophobic and oleophobic coatings were prepared with the aid of a fluorinated acrylate (Fluowet AC 812) and hydrophobic-fumed nanosilica particles. Nanoparticles were added for increasing the surface roughness and also to increase thermal and mechanical properties of the coatings. Coatings were applied on ABS (acrylonitrile–butadiene–styrene) and HIPS (high impact polystyrene) substrates. As the fluorine and nanosilica contents were increased in the formulations, flame retardancy, hydrophobicity, and the oleophobicity of the coatings increased. Coatings were found to be highly thermally stable, highly solvent, and chemically resistant. The surface roughness of the coatings increased with the addition of hydrophobic-fumed nanosilica particles. In addition, the relation between the surface energy and the contact angle of the coatings was investigated.

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