FIXATION OF SOME DIRECT DYES ON GAMMA-IRRADIATED NYLON-6 FABRICS THROUGH TREATMENT WITH CYANURIC CHLORIDE

Cyanuric chloride was utilized as a crosslinking agent in forming a ch emical linkage between some direct dyes and the available sites in the macromolecular structure of nylon-6. This chemical treatment was carr ied out on nylon-6 fabrics before and after being gamma-irradiated in air with different radiation doses. The so-called dye fixation of thre e direct dyes, which contain at least one amino group in their chemica l structure, was assessed in terms of extraction in 50% aqueous soluti on of N, N-dimethylformide. It was found that the dye fixation of the direct dyes under investigation depends essentially on the cyanuric ch loride concentration. However, low concentrations of ca. 1% were found to be sufficient to produce good dye fixation. Moreover, nylon-6 fabr ic when irradiated prior to dyeing and treatment acquire additional dy e fixation. The pH of the dyeing bath and the added solvents were foun d to play a specific role in the dye fixation process. (C) 1997 by Joh n Wiley & Sons, Ltd.