Research On The Facilitation Of Pretreat On TGase Catalyzing ε-PLL Grafted Wool Fabircs

Transglutaminase (TGase) can catalyze the acyl transfer reaction between theγ–carboxyamide group of glutamine (acyl receptor) and the ε–amino group of lysine (acyldonor), which will form the ε–(γ–glutamyl)-lysine cross-links of the protein molecule. Thefunctional modification of the wool realizes via the acyl-transfer reaction catalyzed byTGase.In this research, different methods have been used to promote the catalysis of TGasefor ε-PLL to wool fabrics. It also provide theoretical basis for biological functionalization ofprotein materials including wool and silk.Firstly, subtraction pretreatment was used to break the scale layer of wool. Then additionpre-coating treatment was used to provide more grafting sites of wool surface. The influencesof subtraction pretreatment and addition pre-coating treatment on the TGase-catalyzedgrafting of ε-PLL to wool fabrics were investigated.The results showed that subtraction pretreatments including H2O2, KMnO4and DCCApretreatment could promote the grafting reaction to varying degrees, and DCCA pretreatmentshowed the best effect, followed by KMnO4and H2O2pretreatments. The K/S values andscanning election microscopy results also support the above conclusion. After the graftingreaction, the wettability of the wool fabrics was improved, and the wool fabrics also obtaincertain antibacterial function. Wool fabrics pretreated with DCCA showed the best effect withwetting time of35s and antibacterial rate of staphylococcus aureus of67.63%. During theprocess of DCCA pretreatment, a part of the disulfide bonds were oxidized to cysteine. Thegrafting reaction could improve the heat resistant and hydrophilic properties, and the surfaceZeta potential also increased.After the crosslinking with glutaraldehyde, the molecular weight of casein increasedobviously, and its adsorption and fixation to the wool fabrics were more than the naturalcasein. Coating treatment could improve the wettability of the wool fabrics, and the modifiedcasein showed better wettability than the natural casein.With the crosslinking ofglutaraldehyde and casein to the surface of the wool fabrics, the catalytic effect of TGase wasimproved effectively. After the grafting reaction, the antibacterial rate of staphylococcusaureus of the wool fabrics reached84.30%. The improvement of antibacterial function of thewool fabrics also proved that the crosslinking with glutaraldehyde and coating of caseinscould promote the TGase-catalyzed grafting of ε–PLL onto wool fabrics.