Surface Modification Of Titanium Dioxide And Its Influence In Polycarbonate Properties

Polycarbonate is a kind of engineering plastics with very good integrated pro-perty, but it will also degrade if exposed to ultraviolet for too long, a phenomenon of yellow happens, while the transmittance, gloss and strength and toughness will be gr-eatly reduced. Stable nano-titanium dioxide, with good heat resistance, good UV-shielding ability, it is widely used to improve the anti-aging properties of poly-carbonate, and a lot of in-depth research has been done about this. But the compati-bility problems between the organic and inorganic materials is always existing, the problem can be solved by modifying nano-titanium dioxide, enhanced the compati-bility between it with the polymer.In this paper, we studied preparation of nano-titanium dioxide, the mechanism of organic coating inorganic particles, and the adsorption ability of ultraviolet. And surface modificated nano-titanium were prepared via three method, the results were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), in expect to enhance the compatibility.First, using the sol-gel method and hydrothermal method to prepare nano-sized rutile titanium dioxide particles. Then using a silane-coupling agent KH570,PMMA to graft it to titanium surface by existing hydroxyl, the result graft ratio is7%and11%respectively,the lipophilicity are increased to14.5%and12.3%;prepared by the hydrolysis process of the use of titanium tetrarch-loride, tetrabutyl titanate stearate package The titanium dioxide coated polystyrene titania microspheres, the weight loss rate of60%and65%. The modified nano-particles lipophilic compatibility have been improved to30%, and have90%strong UV absorption within the range of200-350nm.The modified titanium dioxide particles were added through the extruder into engineering plastics polycarbonate, made of composite material, and to study its influence on the mechanical properties of the polycarbonate, the results show that when the addition amount is2-3%, modified titanium dioxide particles can be effect-tively improve impact resistance of the polycarbonate of20%of the tensile properties, rutile titanium dioxide particles are best in increasing anti-aging properities.In this study, PC added with KH570,PMMAmodified nano-titanium dioxide, after aging, the mechanical properties only decreased by3～4%, in contrtast, pure PC or added with other modified titanium dioxide, the mechanical properties may suffer a15%lose.