Enzyme Degumming Of Tussah Cocoon And Enzymatic Modification Of Wool Fabric

With people’s increasing attention to their health, textiles ecological processing is popular and enzymes application in textile processing emerges as the times require. This article includes two parts: degumming of tussah cocoon with papain and 2709 alkaline protease; enzymatic modification of wool fabric with transglutaminase and tyrosinase catalysis grafting of sericin and chitosan quaternary ammonium salt.The process conditions of the enzyme degumming of cocoon were discussed through single factor experiment. The results showed that the degumming rate of tussah cocoon could reach 10% under the follow degumming condition, 4g/L of 2709 alkaline protease, 45℃ and 150 min of degumming, p H 10, 1:25 of liquor ratio. The papain degumming of tussah cocoon’s optimum condition, 6g/L of papain, p H 7, 1:25 of liquor ratio, degumming at 70℃ for 90 min. The surface of the papain degummed tussah cocoon silk fibers was quite smooth and had less damage compared with those of alkaline degummed fibers. Papain had less damage to silk fibers than 2709 alkaline protease.Transglutaminase-catalyzed grafting of sercin and chitosan quaternary ammonium salt onto wool fabric was investigated. Taking the weight gain of wool fabrics as the evaluation index, the process conditions of the grafting reaction were discussed through single factor experiments. The optimal finishing process was obtained: transglutaminase concentration 20%(owf), sericin concentration 200%(owf), chitosan concentration 10%(owf), p H 6, temperature 45℃, time 120 min, and 1:50 liquor ratio. The structure and properties of grafted wool fabrics under the optimal finishing process were measured. The amino analysis results showed that the glutamate content of finished wool fabric decreased. Differential scanning calorimetric results indicated that the thermal stability performance of grafted wool fabrics was slightly improved. The SEM results showed that the wool fibers surface was covered by a layer of thin film, which further proofed that sericin and chitosan quaternary ammonium salt were grafted onto wool fibers. The strength of the grafted wool fabrics increased while the whiteness decreased somewhat. the finished wool fabrics had great than 99% bacterial inhibition rate against both Staphylococcus aureus and Escherichia coli. After 20 times of washing, the grafted wool fabrics still had antibacterial properties.The optimal finishing conditions of tyrosinase-catalyzed wool fabrics were obtained: tyrosinase concentration 2000U/g, sericin concentration 150%(owf), chitosan concentration 15%(owf), p H 6.5, temperature 35℃, time 24 h, and 1:50 liquor ratio. SEM photos showed that the wool fiber surface was covered by a layer of thin film or uneven solid distributions, and the differential scanning calorimetric analysis indicated that the thermal stability performance of grafted wool fabrics was slightly improved, which further proofed that sericin and chitosan quaternary ammonium salt were grafted onto wool fibers. The strength and the crease recovery of grafted wool fabrics increased while the whiteness lowereddown. After 20 times of washing, the grafted wool fabrics still had antibancterial properties.