Improving moisture absorbent and transfer abilities by modifying superfine fiber synthetic leather base with collagen-chrome tannins

The superfine fiber synthetic leather base (SFSLB) is composed of the two components of nylon fibers and polyurethane. SFSLB has excellent performance, especially in terms of mechanical properties. However, compared with native leather, SFSLB has a hot feeling due to its poor moisture absorbent and transfer abilities. So our study proposed a method of grafting collagen-chrome tannins (C-CrT) on nylon fiber in the SFSLB for improving the moisture absorbent and transfer abilities. A three-step surface modification was developed, involving washing pretreatment, sulfuric acid hydrolysis and grafting of C-CrT on SFSLB. The dosage of sulfuric acid and chrome tannins, bath ratio, reaction temperature and the time for collagen permeation and chrome tannin cross-linking were optimized via single-factor experiments. Their efficiency was determined by measuring static water-vapor transmission rate (SWVT) and liquid wicking rate. The results showed that the dosage of sulfuric acid was 15% and chrome tannins was 5%, the bath ratio was 1500%, the reaction temperature was 60℃ and the time for collagen permeation and chrome tannin cross-linking was 3 hours. Under this condition, the SWVT of modified SFSLB was 986 g/m2 · 24 h, and the liquid wicking rate was 1.323 mm/s. Compared with untreated SFSLB, the SWVT and liquid wicking rate of modified SFSLB were improved by 90.35% and 344%, respectively. The static state contact angle, scanning electron microscopy and X-ray photoelectron spectroscopy were used for the determination of sample surface performance, morphology and chemical composition, and states before and after treatment, respectively.