A comparative study on wool bio-antifelting based on different chemical pretreatments

The enzymatic antifelting of wool with proteases, which is referred to as bio-antifelting, has become a promising eco-friendly alternative to conventional chlorination treatment. However, wool bio-antifelting in industrial scale has not been reached so far due to its unsatisfactory shrink-resistance and uncontrolled action in fiber damage. In this paper, the action and mechanism of two kinds of chemical pretreatments, i.e., hydrogen peroxide and dichlorodicyanuric acid pretreatments on the shrink-resistance of protease-treated wool fabrics were investigated and compared. The results show that although hydrogen peroxide treatment could decrease the shrinkage of wool in comparison with untreated one, its contribution to the enhancement of wool bio-antifelting with protease was not remarkable. An effective shrink-resistance can be obtained when the wool fabric was treated with dichlorodicyanuric acid and protease consecutively. Both of the two chemical pretreatments could improve the wettability and whiteness of protease-treated wool. The mechanism of different pretreatments for enhancing wool bio-antifelting with protease was further illustrated and compared via several microscopic analyses such as Allwörden’s reaction, FTIR-ATR and SEM. The comprehensive comparison for wool bio-antifelting based on different chemical pretreatments reveals the difference of hydrogen peroxide and dichlorodicyanuric acid pretreatments in antifelting mechanism, which is valuable for getting a clear understanding and further modification of wool bio-antifelting.