Preparation and Surface Characterization of Polyurethane Hydrogels

In the present study, new hydrogels based on polyurethane (PU) and poly(vinyl alcohol) PVA were obtained by freezing–thawing method from aqueous solution. The surfaces of PU/PVA hydrogels were characterized in terms of porosity, roughness, water swelling, Raman and Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. The average pore size increased from 0.6 μm to 21 μm for pure PVA and the PU/PVA hydrogels. The Raman and ATR-FTIR analysis provided hydrophobic interactions and hydrogen bonds interactions between the hydroxyl groups from PVA with the large number of urethane groups from polyurethane. The incorporation of polyurethane also increased the surface roughness and the swelling water of the PVA hydrogels and made the surface more porous, a desirable feature for biomedical application.