Influence of Organic Treatment Agents on the Thermal Stability of Titanium Dioxide

The influence of several kinds of typical organic treatment agents on the thermal stability of titanium dioxide was investigated.The results exhibited that the thermal stability followed the order:polysiloxane＞ 3-aminopropyltriethoxysilane＞trimethylolpropane＞octyltriethoxysilane＞triethanolamine.The mechanism about the effect of molecular structure of organic treatment agents on the thermal stability of titanium dioxide was studied through thermal gravimetric（TG） analysis and Fourier transform infrared spectroscopy（FTIR） characterization.The results showed that both the decomposition temperature and decomposition mode exerted great influence on the thermal stability of titanium dioxide.Silane coupling agents could form silicon dioxide under heating condition,and formed a coating layer on the surface of titanium dioxide,which improved the thermal stability to a certain extent.But the long carbon chain in the coupling agent would reduce the thermal stability.Organic amine could be doped into titanium dioxide upon heating,which deteriorated the thermal stability of titanium dioxide.The decomposition temperature of polysiloxanes was high due to the Si-O-Si backbone with high bond energy,thus their thermal stability was the best among the common organic treatment agents.They still showed good yellowing resistance at 350 ℃.