Application of green cationic silicon-based gemini surfactants to improve antifungal properties, fiber dispersion and dye absorption of sheepskin

In view of conventional surfactants, cationic silicon-based gemini surfactants possess three more advantages imparted by unique structure. Therefore, in this paper, a series of green cationic silicon-based gemini surfactants (C-m-PSi-C-m) with different hydrophobic chain length (m = 8, 12, 18) were used in sheepskin soaking and dyeing processes firstly. Then the properties of sheepskin after C-m-PSi-C-m treatment were studied and their waste bath was analyzed. Meanwhile, traditional soaking scheme (JFC and commercial fungicide) and commercial dye-fixing agent as comparisons were also used in sheepskin soaking and dyeing processes, respectively. The results showed that all performance of sheepskin after C-12-PSi-C-12 treatment was the most outstanding. Antifungal properties and fiber dispersion of sheepskin after C-12-PSi-C-12 treatment were almost similar to or even better than traditional soaking scheme. C-12-PSi-C-12 was conductive to remove the interfibrillary protein among the collagen fibers, but did less damage to collagen fiber in the soaking process. Most importantly, the dosage of C-12-PSi-C-12 was only half of the traditional soaking scheme, dramatically reducing the use and waste of the resource. Moreover, C-12-PSi-C-12 was beneficial to the absorption and fixation of the dye by sheepskin. Compared with commercial dye-fixing agent, the dye concentration in dyeing waste bath using C-12-PSi-C-12 decreased notablely from 3.13 mg/L to 1.75 mg/L. SoC(12)-PSi-C-12 can replace traditional soaking scheme and commercial dye-fixing agent using in leather soaking and dyeing processes. In short, C-12-PSi-C-12 as a kind of eco-friendly substance has been presented, which can improve antifungal properties, fiber dispersion and dye absorption of sheepskin synchronously, and can reduce environmental pollution and provide the way for sustainable development of cleaner leather processing. (C) 2018 Elsevier Ltd. All rights reserved.