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

Organic-inorganic polyurethane coatings were prepared using two polyester resins and two polyhedral Oligomeric Silsesquixane (PUSS) compounds. The effect of hydroxyl content and PUSS functionality was studied on hardness and scratch resistance. FUR 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. (C) 2015 Elsevier Ltd. All rights reserved.