Preparation and characterization of poly(urethane-siloxane)/titanium-dioxide nanocomposites

This work is focused on preparation of poly(urethane-siloxane)/titanium-dioxide nanocompo-sites (PUSNs) with enhanced features. PUSNs were prepared by the in situ polymerization re-action using titanium-dioxide as a nano-filler in different amounts (1, 2, 3 and 5 wt.%) with respect to the poly(urethane-siloxane) (PUS) matrix. PUS copolymer was based on ?,?-dihy-droxy-ethoxypropyl-poly(dimethylsiloxane), 4,4?-methylenediphenyldiisocyanate and 1,4-bu-tanediole. In order to investigate the influence of TiO2 content on the structure, UV resistance, thermal properties, hydrophobicity and morphology of the prepared PUSNs, FTIR spectro-scopy, UV-Vis diffuse-reflectance spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle measurements, surface free energy (SFE) analysis, water absorption, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed. The PUSNs showed excellent UV resistance, high hydrophobicity, low surface free energy and also higher thermal stability and rougher surface and cross-section relief structure as compared to the pure PUS copolymer. Based on the obtained results it can be concluded that prepared PUSNs could be potentially used as protective coatings.