Fabrication and properties of keratoses/sericin blend films

Abstract

Blend films of keratoses and sericin were prepared using water as a common solvent and glycerol as a plasticizer. An aqueous solution of keratoses extracted from wool via oxidation using peracetic acid was added with different amounts of sericin from silk degumming and blended along with glycerol to obtain films by solution casting method. All the different concentrations of keratoses/silk sericin (KOx/SS) films are observed to be in intact condition. Blend films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermal analysis, water uptake and tensile behavior. Only the cast films of 100% keratoses show a smooth surface indicating good miscibility between keratoses and plasticizer, while increasing the amount of sericin the film surface becomes rough. Fourier transform infrared analysis pointed out that the polymers have no covalent interaction with each other. The addition of glycerol to 100% sericin films strongly decreases their thermal stability changing their secondary structure as shown by FT-IR and thermal analysis. A similar behavior was not seen in keratoses. Sericin plasticized film with glycerol shows low mechanical properties, but the addition of 10% of keratoses to the blend strongly enhances the tensile strength of cast films, while the addition of small amounts sericin to keratoses slightly increases its water uptake.