| Magnetic materials have been widely researched and applied in the various sectors of thenational economy and industrial areas. Traditional magnetic materials are mainly to metaloxides and inorganic materials, along with the economic development, the progress ofindustry and science, people put forward some new requirements to the magnetic materials,such as absorbing properties, weather resistance, etc. Using the magnetic materials as fillersof the coatings which are made of resins, is the new trend of the applications in many areas.At present, UV-curable coatings are widely used because of its advantages, such asconvenient, quick drying and environment protection. However, most of the magneticmaterials are dark, when used in UV-curable coatings, the underlyings of the coatings aredifficult to cure, and this’s a limit in applications. This paper aims to design a newdual-curable resin to achieve a better curing effect when using as colored paint which hasfunctional filler in it. Meanwhile, design and prepare functional powders, which havenano-scale and two-layer core-shell structures, in order to achieve multi-functions, such asmulti-band absorption.The first part of this study is: nanoscale ferroferric oxide powder was prepared byco-precipitation synthesis, and based on this, the powders were coated with a layer of titaniaand silica by sol-gel method. The products were characterized by infrared spectroscopy andX-ray diffraction analyzer, each product was observed by nano-ZS and transmission electronmicroscopy. The results showed that nano Fe3O4powder, varing coated degrees ofFe3O4/TiO2and Fe3O4/SiO2composite nanoparticles were successfully prepared. Theseparticles are regular spherical, higher the coated extent, leads to more easily to reunion. Fe3O4particles have the sizes of12-15nm, and the particle sizes of the composite nanoparticles areincreases slightly with the increase in the amount of coating.The second part of this study is: UV-moisture dual curable silicone hybrid polyurethaneresin and UV-curable epoxy acrylate was prepared. The products of the synthesis process ofthe resin were characterized by infrared spectroscopy, the results proved that the productsobtained were the target products. The influence of different curing time, manner, and theproportion of the reative diluents to the basic physical properties of the coating films was alsostudied. It is found that the dual-cured coating films performed better than the coating filmsobtained by epoxy acrylate in shock strength, this shows that the dual-curable is conducive tothe curing of the bottom. The thermal performances of some films were researched by TGA.The results showed that dual-cured coating film has certainly improved on the thermalperformance by the film before moisture curing. The coating films obtained by epoxyacrylate performed excellent on this, because the bisphenol A structure has a significantcontribution. The third part of this study is: the dual-curable resin and UV-curable epoxy acrylateobtained hereinbefore was mixed with the functional powders to make colored paints ofdifferent formulations. The influence of the amount of the fillers, the reactive diluent ratioand the thickness of the coating films to the film performences was also researched. Theresults showed that, the filler proportion can not be more than30%of the total mass of thevarnish, otherwise the adhension will be decresed. In the proportion of the reactive diluents,when the resin: TMPTA: TPGDA: HDDA: photoinitiator=55:10:10:20:5, the performencesof the films obtained by both resins are the best. In the terms of the thicknesses of the films,due to the opacity to UV light of the fillers, the thickness of the dual-cured coating film isappropriate at50μm, otherwise the adhension will be declined. The adhension of UV-curableepoxy acrylate coatings is worse than dual-curable coatings, this shows that the dual-curablecoatings have a great advantage compared to UV-curable resin in colored paints. The staticmagnetic properties and permittivities of the products of different kinds of powders as fillerswere also have been researched, the results showed that the saturation magnetization of Fe3O4is87.6emu/g, and this value declined slightly when the powders were coated, and thepowders coated by silica can improve the dielectric properties, and on the opposite, thedielectric properties of the powders coated by titanium have been reduced. |
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