Preparation And Application Of Inorganic Nanoparticles/Water Borne Resin Composite

In this paper, method of surface modification about TiO₂ nanoparticles via silane coupling agent and emulsion co-polymerization of styrene-acrylate in the presence of inorganic TiO₂ nanoparticles was studied firstly. The five-unit system of styrene, butyl acrylate, acrylic acid, acrylonitrile and methyl methacrylate was chosen according to their characteristics and role played in emulsion system. Furthermore, influence of monomer proportion, compound emulsifiers consisted of nonionic emulsifier OP and anionic emulsifier SDS, chain transfer agent, initiator, buffer on process of polymerization and properties of emulsion was studied. Effect of polymerization temperature, time and the affixion of TiO₂ nanoparticles on conversion of monomers was studied, and polymerization techniques were confirmed. The results show that when monomer proportion is St (32%)/MMA (20%) /AA (5%)/AN (10%)/n-BA (33%), TiO₂/ (monomers+TiO₂) is 1.5—2.5%, emulsifiers (SDS / OP) is 2%³% (proportion is 1:2), chain transfer agent (DDMC) is 2%, NaHCO₃ is 0.2 0.5%,initiator is 0.6%, deionized water is 45⁵5%, polymerization temperature is about 85 °C,using continuous starved feeding method the emulsion with stable polymerization process and perfect properties can be obtained.The structure and the dispersion properties of TiO₂ nanoparticles were investigated by ? FTIR and TEM. The results show that chemical bonds existed between TiO₂ nanoparticles and modifier and that modified TiO₂ can steadily dispersed in organic solvents. The structure and thermal stability of composite emulsion were studied by TEM and TGA. By TGA analysis it is proved that polymer has been grafted on the surface of nano-TiO₂ particles, moreover, compared with normal emulsion, the grafted emulsion take on higher thermal stability. The TEM photographs indicate that the composite exhibit a core-shell structure with nano- TiO₂ as core and organic polymer as shell. The research results of fungus resistance of latexes indicate that antibacterial percent to both E.coli and staphylococcus aureus are 100%. The properties of latexes were determined as follows: water resistance is 120h; hardness is H grade, viscosity isl6²0s, solid content is 42%, adhesion is the 1st grade.Then, on the basis of research results hereinbefore, three kinds of products including antibacterial green nano-latex paint, nanometer water borne wood coatings and nanometer...