Preparation Of Wool Keratin Solution And Its Application On Anti-Pilling Finishing Of Woolen Fabric

The preparation of aqueous solution of wool keratin from waste wool fiber and its application on anti-pilling finishing of woolen fabric in this thesis aim to make best use of waste resource of wool keratin. Because the wool keratin is non-poisonous and skin-friendly ,The application of wool keratin on finishing of fabric accord with the trend of green and environment friendly textile.There are plenty of disulfide bonds in keratins which form cross-links within or between peptide chains to form the three-dimension network structure, so that natural keratins are insoluable in water or other solvents. In order to obtain aqueous solution of keratin, the disulfide bonds must be cut firstly. In this research, the reduction-C method was used to deoxidize disulfide bonds to get a keratin which contains a great number of free thiol groups. Because these thiol groups are quite easy to be oxidized to reform the disulfide bonds, some proper approaches should be used to modify and protect those thiol groups so as to obtain stable keratin solution.To obtain the high conversion rate, high concentration, relatively high molecular solution ,We use reducing agent dissolve wool keratin from wool fiber with carbamide and SDS (sodium dodecyl sulfate). There are two strengths of this method. Firstly, disulfide bond is the strongest link among the keratin molecular structure, but reducing agent can rupture disulfide bridge effectively. Secondly,the reduction-C method can control the degradative degree of keratin molecular weight. For example, we analyzed the molecular weight of keratin by dialysing the solution with dialysis tubing and we found the molecular weight which was made by the reduction-C method under 60 degrees centigrade is more than 3000,so ,this way is excellent to prepare the relatively high molecular solution .The effect of several factors such as temperature,time ,pH scale,dosage of reducing agent was analyzed,we also compared the different reducing agents including thioglycolic acid and sodium bisulfite, The urea and metallic salt as denatures were also compared. At last ,the optimal process condition was made.The wool keratin solution was applied on woolen fabric directly, it is easy for keratin to form film on the surface of wool fiber because of the similar chemical composition and structure.the keratin film can reduce the directional friction effect of wool fiber and improve the anti-pilling property of woolen fabric. The aqueous solution of keratin was used on the anti-pilling finishing of woolen fabric ,which seemed a little effective, but far from the satisfied effect. On the other hand ,the cost of preparation of aqueous solution of keratin is high, the pretreatment with reducing agent was used to make full use of the wool keratin. Reducing agent can destroy the surface scales more seriously,which let more soluble keratin adhere on wool. When the the keratin film is formed ,it can repair the destroyed surface of wool fiber,then the surface of wool is more smooth and the directional friction effect declines apparently ,so,The anti-pilling property could be improved further if the fabric is pretreated by reducing agent.