Abstract
Two different kinds of HBPs were used in the preparation of nanocomposite materials based on TiO~2~ nanoparticles. One of the HBPs was characterized by the presence of free OH end groups in its structure, while the other one was obtained via a partial modification reaction which allowed to introduce some alkoxysilane functional groups. The TiO~2~ particles were prepared in situ in the polymer solution by means of a sol‐gel process starting from Ti(iOPr)~4~ as precursor. The polymer/TiO~2~ mixture, subsequently coated and cured in the presence of diisocyanate, gave rise to a hard coating. TiO~2~ was found to be dispersed on nanometer scale inside the final coatings obtained from both the polymers, and the TiO~2~ nanocomposite coatings were also characterized by improved thermal and hardness properties compared to TiO~2~ free systems. Still the two different kinds of HBPs showed a different interaction with the TiO~2~ particles, and it has been evidenced that the modification is required to achieve a better dispersion of the particles in the matrix and better properties for the final coating. Thus, by applying the modified HBP, TiO~2~ could be dispersed and stabilized in the polymer matrix as individual nanoparticles of only 6 nm in diameter.
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