Study On The Synthesis And Application Of The Novel Cationic Monomer 3,3'-[1,4-butanediylbis(Oxymethy Lene)]Bis[(3-ethyl)-oxetane]

A novel cationic UV-curable reactive monomer, 3,3?-[1,4-butanediylbis(oxymethylene)]bis[(3-ethyl)-oxetane](marked as: DIOX) was synthesized in this paper. Subsequently, exploring the various influences of DIOX used as reactive monomer in UV-curing formulation on films. The nano-silica was graft-modified by KH-560 and the product was marked as Nano-SiO2-KH560. Meanwhile, the Nano-SiO2-KH560 was added to the UV-curable formulation of DIOX and E-51 and researched the effects of added amount of Nano-SiO2-KH560 on UV-curable inorganic-organic composite films. The detailed contents of this paper were as below:Firstly, DIOX was synthesized with 3-ethyl-3-hydroxymethyl oxetane and 1,4-dibromobutane as raw materials, tera-n-butylammonium bromide as phase-transfer catalysts in the alkaline conditions. The optimum conditions were set as the amount of 1,4-dibromobutane was 0.2mol, the molar ratio of 1,4-dibromobutane and 3-ethyl-3-hydroxylmethyl oxetane was 1:2.5, the amount of tera-n-butylammonium bromide was 2g, the alkaline condition offered by 1.0mol potassium hydroxide and the reaction time was 24 hours at 0?. The molecular structure of DIOX was confirmed by FT-IR and 1H-NMR. Meanwhile, the curable mechanism of the novel cationic reactive monomer was studied. The result showed that, the curing mechanism of the novel monomer is attributed to the cationic ring-open polymerization.Secondly, the DIOX-E51 and DIOX-F51 UV-curable formulation was prepared by DIOX, E-51(or F-51) and UV-6976. The effect of the DIOX content on the diluent of formulation was studied and the result showed that it has the similar dilute compared with commercial common monomers. The water resistant, corrosion resistant, gel fraction, flexibility, pendulum hardness, tensile strength and elongation at break of UV-curable films under different content of DIOX were researched. The effect of photoinitiator content, illumination intensity on curing time and gel fraction were also studied. So in actual production we can gain our targets according to these rules.Thirdly, the nano-silica was graft-modified by KH-560. The effects of weight percentage of KH-560, the reaction temperature and the reaction time on the modification effect were studied. The lipophilic degree was used as the method of evaluation of the modified effects. The optimum conditions were set as the amount of KH-560 was 10wt%, the reaction temperature was 80? and the reaction time was 4h. At the aforementioned conditions, the graft-modified nano-silica owning the best lipophilicity. The SEM showed the graft-modified nano-silica has bigger diameter and excellent dispersibility.Fourthly, a novel inorganic-organic composite film was obtained from the mixture of Nano-SiO2-KH560, DIOX, E-51 and UV-6976 after UV radiated. The effect of amount of Nano-SiO2-KH560 on viscosity of liquid UV-curable mixture and curing time were researched. The influence of amount of Nano-SiO2-KH560 on UV-curing film of mechanical property and acetone resistant were also studied. The results showed that, at the same amount, modified nano-silica much better than unmodified nano-silica. While the content of modified nano-silica was 4wt%, the UV-curable films expressed excellent comprehensive properties.