Curing of polyester powder coating modified with rutile nano-sized titanium dioxide studied by DSC and real-time FT-IR

摘要

Polyester powder coating modified with 2 mass% of rutile nano-sized titanium dioxide (nano-TiO_2) was prepared by melt-blend extrusion method. The nano- TiO_2 dispersion state in the powder coating matrix was analyzed by field emission scanning electron microscopy (FE-SEM), which presented a well dispersion of modified nano-TiO_2 in the polyester powder coating. The effect of nano-TiO_2 on the curing of polyester powder coating was investigated by differential scanning calorimeter (DSC). Kissinger and Crane methods were used to study the activation energy (E) and reaction order (n) of the coating. The results indicated that 2 mass% of nano-TiO_2 additive played a prompting role in the curing of polyester powder coatings, due to the hydroxyl functional groups existed on the surface of nano-TiO_2. Furthermore, real-time Fourier transform infrared (FT-IR) spectroscopy with a heating cell was also employed to record the curing actions, of which results were consistent with the DSC experiments.