Influence of titanium dioxide on the thermal insulation of waterborne intumescent fire protective paints to structural steel

Titanium dioxide (TiO2) is an inevitable ingredient that influences the properties and performance of intumescent paints. The aim of this study is to investigate the effect of TiO2 on the thermal insulation of waterborne intumescent paints. Five intumescent formulae with different weight ratios of TiO2 to ammonium polyphosphate (APP), including paint without TiO2 as a control sample was prepared. Thermal properties and thermal insulation performance of intumescent paints were measured by thermogravimetric analysis (TGA) and customized programmable furnace, respectively. The composition of char was analyzed by using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results showed that ratio of both ingredients (TiO2:APP) play a critical role on the performance of intumescent paints. It is suggested that ratio of slightly excess stoichiometric atomic ratio of titanium to phosphorus (Ti:P) exhibits better thermal insulation of intumescent paints.