Preparation And Characterization Of UV-curable Hybrid Coatings And UV Curable Conductive Adhesive

In this thesis, UV curable nano-silica/epoxy acrylate hybrid coatings and UV curable silver plating copper filled conductive adhesive were prepared and their properties were studied. The detailed research and results were summarized as follows:The nano-silica was anchored by thermal initiator and modified by in situ and grafting polymerization in reactive diluents. Then the high-performance UV curable nano-silica/epoxy acrylate hybrid coatings were prepared by using the mixtures of nano-silica and reactive diluents blended with other raw materials. The structure and properties of the hybrid coatings were studied by FTIR spectroscopy, SEM, TG and test experiment of film performance. The results showed that the polymer chains were combined with nano-silica through chemical bond and the silica nanoparticles were well-dispersed in the hybrid films. The heat resistance, impact resistance, hardness, adhesion, corrosion resistance and optical properties of hybrid coatings were enhanced by the incorporation of nano-silica into epoxy acrylate films. And when the content of nano-silica was 4%, the physical properties of films were excellent.The-CHO group with reducibility was anchored onto the surface of silica by two-step reaction with the starting materials of 3-Aminopropyltriethoxys ilane and glyoxalic acid Then the SiO2/Ag composites with raspberry-like and core-shell morphology were prepared by the redox reaction between the-CHO group and [Ag(TEA)2]+in the silver ammonia solution at the appropriate reaction conditions. The effect of the reaction conditions on the silver content of SiO2/Ag composites was also studied. X-ray diffraction revealed that the surface of SiO2 was surrounded by pure silver, and the silver had face-centered-cubic structure. UV-VIS Spectrum revealed that when silver was deposited on silica spheres, a absorption peak appeared at near 410 nm, and when silver content increased, the peak broadens and red shifted to longer wavelengths.The optimal formula of the UV curable conductive adhesive gained from single factor test was as follows:Silver-plated copper powder 70%,complex photoinitiator 4%, AIBN 2% and KH570 2.5%.And the electrical bulk resistivity of conductive adhesive was 8.9×10-4Ω·cm by using this formula. On the other hand, the tenacity, conductivity and shear strength of conductive adhesive were enhanced by the incorporation of SiO2/Ag composites into conductive adhesive. And when the content of SiO2/Ag composites is 2%, the properties of conductive adhesive were excellent. The electrical bulk resistiv-ity of conductive adhesive was 7.0×10-4Ω·cm and the shear strength of cond-uctive adhesive was 0.95 Mpa.