Nonionic Short-Chain Fluorinated Surfactants in the Fatliquoring of Chrome-Tanned Goat Skin

Surfactants as essential auxiliaries are used in almost all chemical processes in leather production. In this work, a series of nonionic short-chain fluorinated surfactants (Fn-Fn, where n = 2, 4, or 6) were successfully prepared and used as fatliquoring auxiliaries in the fatliquoring process of chrome-tanned goat skin. The chemical structure of these nonionic short-chain fluorinated surfactants was characterized by FTIR and the molecular weight was determined by GPC. The surface tension measurement results revealed that these three fluorinated surfactants showed excellent surface activities. The effect of type and dosage of Fn-Fn as well as fatliquoring temperature on fatliquoring properties of chrome-tanned goat skin were estimated by the softness and physical mechanical properties characteristic of resultant leather. The results revealed that the leather treated with 1 wt% F4-F4 at the fatliquoring temperature of 40oC showed the best overall performance, whose softness and physical mechanical properties were improved significantly. Moreover, the collagen fiber morphology and waterproof performance of leather treated with Fn-Fn were also investigated which showed that the addition of Fn-Fn in the fatliquoring process could promote the loosening of collagen fibers while effectively enhancing the water repellency of the leather surface. Therefore, such types of nonionic short-chain fluorinated surfactants are promising to be as desired fatliquoring auxiliaries in the leather industry.