Synthesis of PEG/TDI/F6 Adducts and Utilization as Water/Oil Repellents and Oily Stain Release Finishes for Cotton Fabric

Abstract

Four polyethylene glycol (PEG)/2,4-toluene diisocyante (TDI)/ perfluorinated aliphatic alcohols mixture (F6) adducts were prepared by reacting equimolar ratios of PEG (300, 600, 1000, or 2000), TDI, and F6 at 90°C for 90 min. All adducts, except that based on PEG 300 were water dispersible. These dispersions were used as water/oil repellent and oily stain release finishes for cotton fabric, via incorporation in a finishing bath containing DMDHEU. Factors affecting finishing process, using an adduct based on PEG 1000, such as DMDHEU concentration (0–60 g/l), adduct concentration (10–40 g/l), curing time (1–5 min), and temperature (140–170°C) were studied. Optimal performance properties of treated fabric, namely wrinkle recovery angle (WRA), %N, water/oil and stain release ratings, tensile strength, and breaking extension, were obtained using a padding bath containing DMDHEU (50 g/l), the adduct (30 g/l), and MgCl₂ · 6H₂O₂ (5 g/l), drying at 100°C/5 min and curing at 160°C/3 min. The inclusion of hydrophilic PEG segments in the adduct structure weakens the hydrophobic effect of perfluorinted segments, where the water repellency rating does not exceed a ceiling of 50, under the conditions employed. However, the adduct has a dual activity, where it repels oily stain in air and releases them during washing. A comparison among performance properties of fabric treated with adducts based on PEG 600, 1000, and 2000, showed that the fabric properties are practically the same, with little drops in WRA, %N, and oil repellency rating upon increasing PEG molecular weight from 600 to 2000.