Keratin hydrolysate as a foaming auxiliary for textile dyeing process

Abstract Keratins are fibrous proteins which are the main constituent of wool fibres. Keratins are abundantly available in nature and also available as by-product from wool industries, horn and hooves from slaughterhouse, feathers from poultry, animal hair from tanneries. [1] Keratin, due to its natural abundance, has found various applications-such as insulation pads, animal feed, chelating agents etc. [2] Proteins are similar to the amphiphilic synthetic surfactants, because they are composed of both hydrophobic and hydrophilic amino acids that afford them a certain degree of surface activity [3]. The purpose of this work is to understand the impact of superheated water hydrolysis on the foaming behavior of keratin hydrolysates, in relation with their applications in textile dyeing. The effect of hydrolysis temperature and the concentration on wool were investigated. Superheated water hydrolysis was carried out in small lab scale rector at temperatures of 130-180 °C, with a material liquor ratio of 1:3-5, for 1 h, to achieve complete solublization of wool in water. The keratin hydrolysate obtained after the hydrolytic treatment consist of polypeptide chains of variable length, which are natural oligomeric surfactants, and can be applied as potential textile auxiliary and can be used as effective foaming agent in textile foam dyeing process. In the investigated variant, hydrolysis is an ecofriendly process in terms of conservation of water, chemicals, and less load on waste water treatments. Keratin hydrolysates are easily biodegradable, and the foam dyeing technology is less adds on technology, resulting in saving of large amounts of water and energy.