(Chicken feathers keratin)/polyurethane membranes

Actually, chicken feathers are considered as waste from the poultry industry; however, 90% of feather structure is constituted by a protein called keratin. In this research, the properties of feather keratin and polyurethane are combined in order to synthesize hybrid synthetic-natural membranes. Both polymers are linked by urethane bonds which are similar to peptide bonds found in proteins. Keratin is incorporated onto the polyurethane matrix by dissolving protein in a salt solution (urea and 2-mercaptoethanol) at different concentrations: 11, 13, 15, 17, 19, and 21% (w/w). In order to know the effect of urea on membranes, keratin is incorporated to polyurethane in two ways; as keratin salt solution and after dialyzing. Both membrane types were characterized by Scanning Electron Microscopy (SEM) to observe their morphologic changes. Fourier Transformed Infrared Spectroscopy (FT-IR), Termogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC) were used to study membrane structures. Results show that keratin is grafted in polyurethane and, therefore, there is an influence of amino acids through the amino and carboxylic groups (NH and COOH) into the synthetic polymer structure. According with characterization results, the obtained membranes are functional materials that can be useful in diverse applications, among them the separation process can be emphasized.