Effects of graft modification on the water solubility, apparent viscosity, and adhesion of feather keratin for warp sizing

Biodegradable and inexpensive sizing agents were developed through graft polymerization of native feather keratin with acrylic acid (AA). Feathers are available in large quantities at low price and more than 80% of them are keratin. However, poor water solubility of native feather keratin under neutral condition greatly limits the use of feather keratin as warp sizes in textile industry. In the investigation, effects of graft modification on the properties of feather keratin were studied in terms of water solubility, apparent viscosity, and adhesion to fibers. It was found that grafting appropriate amounts of AA monomers onto the molecular chains of feather keratin was an effective method to improve the water solubility of feather keratin under neutral condition. The modification could make the grafted feather keratin obtain better sizing properties than native feather keratin and serve for more fiber variety of yarns as a new bio-based sizing agent.