Promotional effect of 1‐butyl‐3‐methylimidazolium chloride ionic liquid on the enzymatic finishing of wool

Abstract

To improve the effects of protease finishing on wool, 1-butyl-3-methylimidazolium chloride ionic liquid was employed as a pretreatment reagent. It was found that ionic liquid pretreatment significantly changed the wool surface characteristics. The Allwördern reaction showed that the epicuticle layer was damaged by the ionic liquid, and X-ray photoelectron spectroscopy analysis further demonstrated that the surface elemental composition was significantly changed. Ionic liquid pretreatment remarkably improved the accessibility of protease to the wool and thus accelerated the hydrolysis rate of keratin. The properties of wool fabric after combined processing were also changed. Dyeability results showed that the color depth was increased but the wet rubbing and washing fastness of wool fabrics showed a decreased half grade. The wettability results demonstrate that the contact angle was further reduced after the comprehensive treatment because of the exposure of more proteins under the fatty-acid layer. In addition, the shrink proofing of wool fabric was also enhanced after combined processing. In summary, ionic liquid modification presents a promising pretreatment method for protease processing of wool.

Enzymatic Thiol–Ene Click Reaction: An Eco-Friendly Approach for MPEGMA-Grafted Modification of Wool Fibers

“…25,26 Due to the presence of the lipid layer, the C content of the wool fiber surface is 85.05%, which is much higher than the C content in the bulk of the wool (about 50%). 27 Compared with untreated wool, the C/N and C/S ratios of L-cysteine-pretreated wool decreased, showing that the content of the C element was reduced after L-cysteine-pretreatment. The C/N and C/S ratios of wool fabrics increased after the treatment with MPEGMA.…”

“…The results are shown in Figure and Table . According to the XPS spectra of wool fabrics (Figure ), four characteristic peaks can be observed in the range of 0–600 eV of the wool XPS energy spectrum for the C 1s peak (285 eV), N 1s peak (400 eV), O 1s (532 eV), and S (164 eV). , Due to the presence of the lipid layer, the C content of the wool fiber surface is 85.05%, which is much higher than the C content in the bulk of the wool (about 50%) . Compared with untreated wool, the C/N and C/S ratios of l -cysteine-pretreated wool decreased, showing that the content of the C element was reduced after l -cysteine-pretreatment.…”

“…5), four characteristic peaks can be observed in the range of 0-600e V of wool XPS energy spectrum for C 1s peak (285e V), N 1s peak (400e V), O 1s (532e V) and S (164e V) 25,26 . Due to the presence of the lipid layer, the C content of the wool fiber surface is 85.05 %, which is much higher than the C content in the bulk of the wool (about 50%) 27 . Based on the results from Raman spectra and XPS analysis, the disulfide bonds in wool fiber were reduced to thiol groups and the thiol-ene click reaction between MPEGMA and reduced wool could be evidently confirmed, implying that HRP has initiated the grafting modification of wool with MPEGMA through thiol-ene click reaction.…”

Synergetic Effects of Liquid Ammonia, Protease, and Polyurethane Nano-Emulsion on Improving Shrink Resistance of Wool

“…The peak at 9.27° is the diffraction peak formed by the synergy of α and β crystals, while the peak at 20.2° is the diffraction peak of β crystals. 35,36 After liquid ammonia and protease treatment, the intensity of the peaks was still decreased, which means that the crystallinity of wool was changed. Furthermore, the intensity of the peaks is still decreased after polyurethane finishing.…”

Effect of liquid ammonia and protease on surface modification and shrink resistance of wool

“…The content of C is 76.47%, which is obviously higher than that of the whole fiber (49%-52%). 21 After liquid ammonia treatment, nitrogen content of wool was increased, while sulfur content decreased more and slightly decreased of carbon and oxygen. However, after the combining treatment of liquid ammonia and protease, the content of carbon and sulfur decreased, while oxygen and nitrogen contents increased.…”