Use of nanoindentaion and nanoscratch experiments to reveal the mechanical behavior of POSS containing polyurethane nanocomposite coatings: The role of functionality

• Addition of POSS with different hydroxyl functionality.
• Investigating the scratch and indentation behavior of nanocomposite films.
• Compatibility of POSS and polyurethane system and its effect on transparency.

Organic–inorganic polyurethane coatings were prepared using two polyester resins and two polyhedral Oligomeric Silsesquixane (POSS) compounds. The effect of hydroxyl content and POSS functionality was studied on hardness and scratch resistance. FTIR spectroscopy was used to reveal bond formation between isocyanate and hydroxyl groups. Vickers hardness, nanoindentaion and nanoscratch experiments were performed to study the mechanical properties of the hybrids. The results showed that intrinsic hardness of POSS affected the crosslink density, the result of which was increased free volume and improved scratch resistance of POSS/PU hybrid coatings. This behavior was dependent on the hydroxyl percent of the polyol.

Figure optionsDownload high-quality image (144 K)Download as PowerPoint slide