In-situ Solvothermal Synthesis And Characterization Of Epoxy Nanocomposites And Research Of Functional Properties

In this paper, a solvothermal process was developed to in-situ prepare epoxy (EP)/ZnS nanocomposites and epoxy (EP)/TiO₂ nanocomposites. The preparation, morphology and properties of these nanocomposites have been studied in detail.First, epoxy coated ZnS nano-particles were synthesized through hydrothermal process, and then epoxy/ZnS nanocomposites with different ZnS contents were prepared. XRD and TEM results prove that ZnS nanoparticles coated with epoxy have been successfully synthesized, and UV-Vis spectra showed that nano-ZnS has a strong UV absorbance in UV wavelength. The effects of ZnS content on UV absorbance and UV transmittance of nanocomposites as well as TGA curves of different samples with different UV irradiation time were studied in detail. The results demonstrated that epoxy/ZnS nanocomposites show strong UV resistance. In addition, the mechanism of UV resistance improvement of epoxy/ZnS nanocomposites has been discussed. The refractive index of epoxy/ZnS nanocomposites has been investigated as well.Second, transparent EP/TiO₂ nanocomposites were prepared through two-step approach. Specifically, EP/TiO₂ hybrid precursors were synthesized by in-situ solvothermal process and then further cured to obtain EP/TiO₂ nanocomposites. Tetrabutyl titanate (TBT) was employed as precursors to prepare TiO₂ nanoparticles in liquid epoxy monomer as disperse medium. KH560 was added as a coupling agent to improve interfacial interaction between the epoxy matrix and in-situ-formed TiO₂ nanoparticles and simultaneously as a diluent to reduce viscosity of epoxy matrix. FTIR and XRD results prove that TiO₂ nanoparticles wee successfully in-situ formed in epoxy matrix through the solvothermal process. At the same time, the morphology and dispersion EP/TiO₂ hybrids have been studied of by optical photos and FE-SEM. The effect of TBT content on curing dynamics of EP/TiO₂ nanocomposites has been investigated. The TGA, DSC and gel content measurements showed that EP/TiO₂ hybrid precursors were fully cured with the glass transition temperature decreasing gradually. The effects of TiO₂ contents on the transparency, UV absorbance, surface properties and low-temperature impact properties of EP/TiO₂ nanocomposites as well as the SEM appearance of ruptured surfaces have been studied in detail.