Valorization of Chicken Feather Waste: Fabrication of Keratin-Chitosan Biofilms

According to scientists, keratin is one of the most abundant fibrous materials in nature after cellulose and chitin in the world. Several nature fibrous materials have a wide range of application starting from biomedical application to the construction sector, and especially the textile sector. The uses of natural fibers in these sectors are economical for increasing their specific properties, such as antibacterial properties, flexibility, tensile strength, shear strength, toughness, etc. This paper presented a new type of keratin-chitosan biofilms with the separation of keratin from waste chicken feathers. The laboratory-scale keratin extraction process was designed. The keratin extraction percentage of different lixiviants (NaOH; NaOH+Na2S; Na2S) were studied and compared each other to understand the reaction process. The chosen reaction parameters were lixiviant concentration, reaction time, and temperature in an attempt to figure out their effects on the extraction of keratin. The highest extraction value was achieved at 60 degrees C and 400 rpm for 6 h, and 0.5 M Na2S per 5 g of chicken feather powder. After obtaining keratin powder from the chicken feather powder, the keratin and chitosan powders were mixed in a certain ratio. Afterwards the polyvinyl alcohol was added into the mixture of keratin and chitosan at 100 degrees C until forming the biofilms. The properties and structure of the biofilms were characterized and antibacterial properties of films were examined. Owing to its enormous extraction performance using common and cheap chemicals and simple equipment at ambient conditions, the pile processing method has great promise for the keratin bio-waste's industrially.