Chemical Modification Of Proteases For The Felting And Shrinking Resistance Of Wool

Wool is a natural protein fiber, which have many good features,such as great flexible, shiny and soft, warm and good moisture resistance. However, the peculiar cuticle layer structure of wool makes the fabric easy to felting and shrinking resistance, itching sensation, affecting wearability. With the increasingly concerned about environmental issues in the world today, a protease anti-felting method is expected to replace the traditional chlorination ways. Wool fabrics treated by protease, which can effectively strip the cuticle layer of wool,acquire good anti-felting performance. After protease treatment, the fabric’s smooth feel and softness, fullness of fabric are greatly improved. However, this method have a uneven treatment and serious damage to the wool fiber, remained to be further studied.This paper attempts to graft the polymer method of protease modified organisms, increasing the molecular weight of protease,。the protease can be modified which just get into the cuticle layer of wool and not spread into the cortex, thereby stripping the cuticle layer of wool to play anti-felting effect. This article also examined the amount of polymer modified process, the amount of protease, activation time, modification time, pH, temperature on the properties of protease modified.This research firstly use carbodiimide to activate the carboxyl of Eudragit L100, and then,through the covalent bond of the alkaline protease, the carboxyl of Eudragit L100connect to the amino of Esperase8.0L to form the modified protease Eudragit-Esperase. The change make Esperase8.0L protease molecular weight increased from4.1-6.5kDa to27kDa more. The article also modified the process of protease in-depth study on the impact of protease activity in the process. Several important factors were analyzed in the experiments to determine how to maintain optimal activity of the protease in the modified process. After modification, the research use natural protease and modified protease Esperase8.0L EE respectively for anti-felting wool fabric finishing. Dealing with natural protease Esperase8.0L wool fabrics obtained, compared to wool fabrics treated by the modified protease EE, fabric weight loss rate decreased21.90%,13.10%fabric tensile breaking strength increased, which indicate that modified proteases can significantly reduce the Eudragit-Esperase wool fiber strength damage. Meanwhile, the area felting of wool fabrics treated by modified protease EE decrease from the original rate of8.12%to0.89%, indicating that using the modified protease EE to finish wool fabrics can give a good anti-felting properties.