Synthesis, Characterization And Performances Of Waterborne Polyurethane Coatings And PVDF Based Hydrophobic Coatings

This dissertation includes three sections: synthesis and UV curing of waterborneacrylated polyurethane, synthesis and ambient curing of amine terminated waterbornepolyurethane with waterborne epoxy resin, and preparation and performances ofhydrophobic coating based on PVDF. The main research work is shown below.1. A series of UV curable waterborne acrylated polyurethanes were synthesizedfrom toluene diisocyanate (TDI), polyethylene glycol (PEG), 2,2-dimethylolpropionicacid (DMPA) and β-hydroxyethyl methacrylate (HEMA). The factors influencingparticle size of the dispersions were investigated by DSL and TEM. The contents ofurethane and allophanate linkages in the polymer were analyzed by 1H-NMR. Thethermal properties and mechanical performances of UV-cured polyurethane coatingswere related to the content of acrylate groups in the polymer.2. Two series of amine terminated waterborne polyurethanes were prepared fromTDI, PEG, DMPA with hydrazine and ethylene diamine as extenders, respectively.The structure of polyurethane prepolymers was characterized by 1H-NMR, GPC andIR. The results indicated that the polyurethane cured coatings with γ-glycidoxypropyltriethoxysilane (KH560) as the crosslinker demonstrated goodmechanical properties and high water resistance. However, the cured coatings withaqueous epoxy resin as the crosslinker had low hardness.3. Hydrophobic coatings were prepared from PVDF, nano-CaCO3 andheptadecafluorodecyltrimethoxysilane (FAS-17). FAS-17 was found to improve thesurface contact angle for water without any effect on the mechanical performances ofcoatings. SEM indicated that FAS-17 can help the dispersion of CaCO3 in PVDF andincrease the roughness of the coating surface. The formation of frosting was greatlyretarded on the hydrophobic coating, compared with that on naked copper.