Formaldehyde-free durable flame-retardant finishing for polyester/cotton blended fabrics through chemical grafting and cross-linking
Yonghua Lu, Qian Tang, Yan Yang, Shuo Diao, Guangxian Zhang
Abstract
A neotype high molecule reactive flame retardant , phosphoramide ammonium salt of polyethyleneimine derivatives for polyester/cotton (TC) blended fabrics was synthesized, and its structure and thermostability was characterized by 1 H, 31 P- nuclear magnetism resonance ( 1 H NMR, 31 P NMR), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) analysis. Results of FTIR, X-ray photoelectric spectrometer, surface morphology and energy dispersive X-ray and durability testing for the treated TC samples indicated that the flame retardants uniformly grafted onto the surface of fabrics especially on cellulose fibers. Vertical flame test, limiting oxygen index (LOI) values, conical calorimetric measurements showed a good flame retardancy of the treated fabrics. LOI of the treated fabric increased to 28.8 % at 14.8 % loading rate of flame retardants, and the loading rate remained above 93 % after 50 laundering cycles under AATCC 61–2013 3A standard. TG and TG-FTIR results suggested that the synthesized high molecular compounds mainly performed a condensed phase mechanism of flame retardancy. The finished fabrics tremendously sustained the original tensile strength. These results revealed that this high molecule reactive phosphoramide ammonium phosphate compounds can effectively endow a stable flame retardancy to the composite polyester/cotton blended textiles.