Cationic organofluorosilicone as deepening agent in the application of dyed polyester fabric

ABSTRACT Polyester fabrics are usually difficult in dyeing deeply due to their dense structure and high surface refractive index, and deepening finishing is an effective method to obtain dark polyester fabrics. In this article, octamethyl cyclotetrasiloxane (D4), 1,3,5‐tris(3,3,3‐trifluoropropyl)‐methylcyclotrisiloxane (D3F), and silane coupling agent KH‐902 were used as main monomers to synthesize organic fluorosilicone, and further to prepare cationic organofluorosilicone (COFS) and COFS darkening agent. FTIR and 1H‐NMR were used to characterize the structure of synthetic products. The finishing experiments confirmed that COFS darkening agent had good shade darkening on dyed polyester fabrics with small color change. The optimum conditions of deepening finishing were COFS darkening agent concentration of 20%, the pick‐up of 85%, and the curing temperature of 180 °C. After finishing, the dyed fabric had no lowering effect on color fastness, all at grade 4 or above. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48208.