The Preparation And Study Of A Novel Photo Catalytic Aqueous Polyurethane Material

Aqueous polyurethane(apu) are serving in most of fields of modern society because of its many advantages, such as safety, nontoxicity, easily processed, good flexibility, bearing to low temperature, free-fatigue and Chemical Resistance. Nano titanium dioxide is one of the most popular nano photo catalyst, which can kill bacteria and decompose deleterious organic compounds effectively with the characteristics of long-term effectivity , broad application, low cost and convenience. In this paper, the nano titanium dioxide are combined with the aqueous polyurethane to be prepared a novel photo catalytic aqueous Polyurethane material.Because the nano particles of titanium dioxide are easily agglomerated by high surface energy in the apu emulsion, the efficiency of the photo catalysis are always reduced awfully. Meanwhile, the spectral response range of titanium dioxide is limited to the Ultraviolet spectrum, so the natural light and fluorescence lamp light in the room can't be utilized sufficiently. So improving the dispersibility of the nano particles of titanium dioxide in apu emulsion and expanding the spectral response range of titanium dioxide are the key to manufacture the highly efficient photo catalytic aqueous Polyurethane material.In this paper, the Sol-gel method is used to prepare SiO₂/TiO₂, and adulterating Fe³⁺ to the SiO₂/TiO₂ to prepare Fe³⁺/SiO₂/TiO₂ which are dispersed to apu emulsion to prepare SiO₂/TiO₂-PU and Fe₃₊/SiO₂/TiO₂-PU.According to Fourier transform infrared spectroscopy (FTIR), X-ray diffraction(XRD) and transmission electronic microscope(TEM),we can find SiC>2 has been coated onto the surface of TiO2 successfully, the average diameters of the composite photo-catalyst reach 90nm; Fe3+ is infiltrated into the crystal lattice of TiO2; crystallites becomes smaller. Spectrophotometry shows that SiO2-coating and being modified by the polyethleneglycol-800(PEG-800),sodium silicate and Sodium dodecylsulfonate(SDS) can improve the dispersibility of the SiC^/TiCh and Fe3+/Si02/Ti02 in apu emulsion, especially, when the content of T1O2 reaches to 20% and adding 1.0% SDS. The Mechanic test indicates that when the content of nano composite photo catalyst reaches to 0.6% to 0.8%,the mechanic properties of SiO2/TiO2-PU and Fe3+/Si02/Ti02-PU are best.UV-vis spectra and fluorescence tests reveal that the UV-visible absorption side of Fe3+/SiO2/TiO2 move from 349 nm to 410 nm which indicate that the capability of photo catalysis are toned up by adulteration of Fe3+.Rhodamine B test shows when adding 1.0% to 1.5% of the composite photo catalyst, SiO2/TiO2-Pu and Fe3+/Si02/Ti02-PU exhibit the best capability of photo catalysis, and with the same contents of composite photo catalyst, adulteration of Fe3+ can increase the degradation ratio of Rhodamine B best by Fe3+/Si0?/Ti02-PU,which can reach to 94.62%. The bacterial inhibition test experiment shows the SiO2/TiO2-PU is 60% to 70% , and the Fe3+/SiO2/TiO2-PU can overcome 80%,the top is 90%.It means Fe3+/Si02/Ti02-PU has an excellent antibacterial capability, Which can maintain under the natural light and fluorescence lamp light.