MODIFICATION OF POLYAMIDE FIBERS (PA6) BY GRAFTING POLYACRYLAMIDE (PAM)

The grafting of polyacrylamide (PAM) onto PA6 knitted fabric in aqueous systems under the atmosphere of nitrogen or air was examined. The grafting process was initiated by oxidation with air oxygen, forming hydroperoxide groups. Effects of time and temperature of oxidation and of the grafting conditions, such as concentration of monomer, temperature, and time, on the rate and degree of grafting were determined. The optimum grafting conditions, ensuring the minimum amount of homopolymer, were found (oxidation temperature 413 K, oxidation time 10 min, grafting temperature under nitrogen 353-373 K, grafting time 1 h, monomer concentration 0.7 mol/dm(3)). The activation energy of the grafting under nitrogen and air at 313-373 K was found to be 25.74 and 42.25 kJ/mol, respectively. The hydroscopicity, capillarity, disperse dye absorption, and electrical resistance of the modified PA-6 fabrics were determined. Some improvement of these properties was observed, depending on the degree of PAM grafting and the type of posttreatment with hydrazine and 3-bromopropionic acid. (C) 1995 John Wiley & Sons, Inc.