Study On Fluorine Siloxane Modified Nano-SiO₂Heat-resistent Super-hydrophobic Coatings

Superhydrophobic surfaces having unique characters such as antifouling, waterproof, se-lf-cleaning and so on, have been applied in mang fields like auto industry, building trades and national defense. The siloxane or fluoride materials having the lowest surface in the nature are one of the important materials to prepare superhydrophobic surfaces. Howver, they have low adhesion with mental or resin composites owing to their low surface energy. In this thesis, the heat resistant coatings were developed by using nan-SiO2particle functionated by fluorinated siloxane as filler and polyarylether blocked with polysiloxane as matrix for protecting the outside surface of high speed aircraft.Firstly, the nano-SiO2was modified by (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxy-silane (shorted as FAS-SiO2). The structure was characterized by FT-IR. In order to investigate the hydrophobic property of FAS-SiO2, the coating having FAS-SiO2and polyacrylate as matrix, synthesized by methyl methacrylate, n-butylacrylate, acrylicacid and hydroxyethyl methacrylate through free radical polymerization, was prepared. The effect of the content of FAS-SiO2in the coating formulate and different substrate on the properties of the resulted coating were studied. The results showed that the coating exhibit superhydrophobic property when covered by FAS-SiO2particle.Then biphenyl-contaning polyethersulfone-b-fluoride polysiloxane (PBES-b-FPSO) was prepared through nucelophilic displacement reaction, subsequently hydrosilylation and the condensation reaction. The struct-ure of the product has been proved by1H-NMR、FT-IR and19F-NMR. The superhydrophobic surfaces were prepared with FAS-SiO2as filler and PSU-b-FPSO as matrix. The effect of the content of FAS-SiO2in the coating formulate and different substrate on the properties of the resulted coating were studied. The results showed that the water contact angel of155°was obtained when PSU-b-FPSO:FAS-SiO2was1:1(wt) coated on glass or metal. When the coating was treated under200℃for one hour, the water contact angel of the coating reduced to147°.In order to improve the heat-resistent performance of the coating, poly(pthalazinone ether nitrile)-b-fluoride polysiloxane (PPEN-b-FPSO) was prepared through nucelophilic displacem-ent reaction, subsequently hydrosilylation and the condensation reaction. The structure of the product has been proved by1H-NMR、FT-IR and19F-NMR, respectively. The effects of reaction temperature and time on the yiled of the target product were investigated. The superhydrophobic surfaces were prepared with FAS-SiO2as filler and PPEN-b-FPSO as matrix. The effect of the content of FAS-SiO2in the coating formulate and different substrate on the properties of the resulted coating were studied. The results showed that the water contact angel of159°was obtained when PPEN-b-FPSO:FAS-SiO2was1:1(wt) coated on glass or metal. The resulting coating still showed excellent super-hydrophobicity with the water contact angel of155°after heating at200℃for one hour.