| The research on waterborne acrylic resin modified by montmorillonite, fluoropolymer and bend with waterborne epoxy emulsion was not only of theoretical value, but also of great industrial value and environmental significance. However, waterborne acrylic emulsion could not catch up the solvent coating in mechanical properties, adhesion, water resistance, acid and alkali resistance and heat resistance. Therefore, the application of acrylic emulsion was limited at many areas. Aiming at the difficulties in acrylic emulsion, the research was focused on the relationship between resin structure and its performance. The organic montmorillonite and composite emulsion were designed and prepared. The properties of films, such as adhesion and water resistance were improved after modified by bending with epoxy emulsion.The main contents were described as follows:(1) The organic-montmorillonites (OMMTs) were prepared by ion exchanging sodium-montmorillonite (Na-MMT) with cetyl trimethyl ammonium bromide (CTAB) or the cationic Gemini surfactants (Gemini C16). The OMMTs were characterized by Fourier transform infrared spectrum (FTIR), thermo-gravimetric analyses (TG), X-ray diffraction (XRD), transmission electron microscopy (TEM) and dispersion measurement. The results indicated that the surfactants had been successfully intercalated into MMT layers and/or adsorbed on the surface of MMT and interlayer space (d001) of Na-MMT enhanced. The dispersion of MMT was improved in butyl acrylate and liquid paraffin because the cationic surfactants had intercalated into MMT layers to change the polarity of MMT from hydrophilic to hydrophobic.(2) Polyfluorine-acrylate composite emulsion was prepared by pre-emulsion polymerization of using methyl methacrylate (MMA) and butyl acrylate (BA) as main monomers, hexafluorobutyl acrylate (HFBM) as fuctional monomers. The ratio of anionic emulsifier and non-ionic emulsifier, and the dosages of initiator, HFBM on the properties of the emulsion were studied. The influences of the amount of HFBM on the mechanical properties of latex film were also discussed. The analytical results indicated the preparation of polyfluorine-acrylate composite emulsion had high conversion (90.42%) and the emulsion had less emulsion coagulating rate (0.72%) when mass ratio of anionic and non-ionic emulsifier was 3:2 in the system of composit emulsifier, the amount of initiator was 1 wt%, the HFBM was 9 wt%. (3) Poly(fluorine-acrylate)/montmorillonite (PFA/MMT) composite emulsion was prepared by situ intercalation and pre-emulsion polymerization. The thesis characterized the structure of resin by FTIR, TG, XRD and TEM and discussed the influences of the amount of OMMT on monomer conversion and coagulating rate, emulsion stability and the hardness, water absoption and mechanical properties of the latex film. The analytical results indicated that the emulsion had better stability and the film had lower water absorption, higher hardness, and better mechanic prepertise when the amount of OMMT was 2 wt%.(4) The PFA/MMT composite emulsion was blended with the epoxy emulsion in order to obtain the better film. The different epoxy emulsions and curing agents were selected and the amount of epoxy resin on the films properties were also discussed. The analytical results indicated that the properties of blended film were improved in water resistance, hardness, adhension, impact strength, flexibility and abrasion resistance when compared with the PFA/MMT film.
|
PDF Full Text Request