Preparation For 3,3'-(Oxydimethanediyl)Bis(3-ethyl) Oxetane And Study On UV-curable Properties

The monomer of Oxetanes, which is not only can participate in the curing,also can be added into UV curing system as diluent, the earliest study of such reactive monomer was in Japan, and it is rarely reported in domestic about oxetanes monomers and the monomers used in UV curable material even rarely. This article synthesized a novel reactive monomer 3,3'-[oxydimethylene]bis[3-ethyl] oxetane(DOX), and add it in UV curing systems were studied and its specific research projects are as follows:First, We use di-trimethylolpropane(DTMP) and diethyl carbonate(DEC) as material, K2CO3 as catalyst, and synthesized a novel reactive monomer-3,3'-[oxydimethylene] bis[3-ethyl] oxetane, and were characterized by NMR and IR. By studying on the process of the synthesis, we found the optimal reaction conditions for this reaction are, DTMP: DEC = 1.0: 2.1( molar ratio, DTMP was 0.3mol), 15.0 g K2CO3, the reaction temperature was 110?. At present, yield was 49.2%.Second, the DOX was respectively added to the bisphenol A epoxy resins(E-51) and phenolic epoxy resins(F-51), it was found that DOX can effectively reduce the viscosity of the epoxy resin, having good dilution effect. We also determine the two systems gel fraction of cured films showed that the UVI6976 of 5%, the highest rate of the gel system, and photocurable was also best. After, the DOX was added to the E51 cationic photo-curable material, founding when E51: DOX was 4: 1, UVI6976 was 5%, elongation at break of the UV curable material up to 9.22%, the maximum tensile strength of 24.82 M Pa, impact strength was 14kg·cm, flexibility was 6%, and has good chemical resistance and heat reswastance; and the same ratio under cationic photo- curable material(F51: DOX was 4: 1, UVI6976 was 5%) for mechanical testing, showing excellent impact resistance, up to 15kg·cm, the tensile strength up to 25.10 MPa, elongation at break higher, too, at 9.13%, and flexibility of 5 axis rod.Finally, Surface modified of nano-SiO2 by Silane coupling agentthe KH560, which was added into the UV-curable materials(E51: DOX was 4: 1, UVI6976 5%), founding that when modified SiO2 was 3%, the tensile strength of the cured material was increased to 43 MPa, the impact strength up to 25kg·cm, the elongation at break also increased to 12.35%; while the modified nano-SiO2 was added to F51: DOX was 4: 1, UVI6976 was 5% of UV-curable materials, the tensile strength, elongation, impact strength also have a more substantial increase, especially tensile strength was 45 MPa, nearly doubled. Fully demonstrated the appropriate amount of modified nano-SiO2 added to epoxy resins, will has good dispersion in the resin, and with toughening enhancement.