| In this paper, a new type of long chain silane coupling agent with a methacryloxypropyl terminal group and long polyether chain was synthesized. SiO2 nanoparticles modified with the above silane coupling agent were added into the UV curable adhesive system to improve its adhension performances. The effects of SiO2 nanoparticles on the viscosity, curing rate and mechanical properties of the UV curable adhesive were investigated.The long chain silane coupling agent(methacrylate polyether propyl) triethoxysilane(MAPPTES) was synthesized by two steps. In the first step, ally propyl polyether was reacted with tirethoxysilane to form the hydroxy polyether propyl triethoxysilane in the presence of choloroplaticnic acid as catalyst. Then in the second step, the (hydroxy polyether propyl) triethoxysilane was further reacted with methacrylate chloride(MAC) in tetramethylene oxide to obtain the final product, using triethylamine as HC1 obsorber. The silane coupling agent was characterized by FT-IR and H NMR. The reaction temperation, raction time and molecular weight of polyether were investigated and the optimal reaction conditions were obtained.The SiO2 nanoparticles were transferred from aqueous dispersion to isopropanol dispersion by azeotropic distillation and the SiO2 nanoparticles were thus become both hydrophobic and hydrophilic. Further, modification of SiO2 nanoparticles were conducted in isopropanol with KH570 and the new synthesized silane coupling agent(MAPPTES400, MAPPTES600, MAPPTES1000). Respectivelly, the modified SiO2 nanoparticles were characterized by FT-IR and TGA. Based on the TEM analysis, modified SiO2 nanoparticles by the above four coupling agents all can be well dispersed with the diameter of 1020 nm in isopropanol.The effects of the coupling agent on the surface modification of SiO2 nanoparticles were evaluated by silanol titration. When using MAPPTES600 as modification agent of SiO nanoparticles, the silanol reduced simultaneously with the increasing amount of MAPPTES600 and the optimal amount of MAPPTES600 was 15%. With the same mass percent of silane coupling agent, it was found that the apparent silanol of SiO2 nanoparticles was smallest when using MAPPTES1000 as SiO2 nanoparticles modification agent, which had a more molecular weight. This was because that the polyether chain can also wrap the SiO2 nanoparticles and form by hydrogen bond with the silanol.The dispersion of SiO2 nanoparticles in UV curable adhesive after curing was observated by TEM analysis. Aggregators of unmodifed SiO2 particles with the diameter of 5001000nm were found in the cured adhesive system, while the KH570 modified SiO2 nanoparticles formed smaller aggregators with the diameter of 100300nm in the cured adhesive. It was found that the MAPPTES modified SiO2 can well dispersed with the diameter of 1020nm. The optimal content of nano SiO2 was 2% based on the mass of adhesive and SiO2 nanoparticles would aggregate when adding more.The addition of SiO2 nanoparticles to the adhesive increased the viscosity of UV curable adhesive system. It was found that the viscosity would be reduced when the SiO2 nano partilces were modificed by silane coupling agent and the best modificationagent was MAPPTES1000 because of the improved the compatibility of nanopartilces and adhesive bulk.The tensile strength and tear strength all increased first and then redused when SiCh nanoparticles were added to the UV curable adhesive and the optimal content of S1O2 nanoparticles was 2%. It was found that the tensile strength and tear strength improved when the SiC>2 nanoparticles was modified by silane coulping agent. When using MAPPTES1000 as the modification agent, the tensile strength could be increased about 29.5% and the tear strength increased about 38.4%.The curing rate of UV curable adhesive decreased when adding S1O2 nanoparticles owe into the absorption of UV rays by the SiO2 nanoparticles. It was found that the curing rate could be improved when the SiC>2 nanoparticles were modified by silane coulping agent.
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