Novel azobenzene derivatives containing a glucopyranoside moiety. Part II : dyeing properties

Novel azobenzene dyes containing a glucopyranoside moiety were applied to polyethylene terephtalate and cellulose diacetate fibres. Isothermal rate-of-dyeing curves at different temperatures, calculations of the apparent activation energies, light and dry heating colourfastness are reported for polyester. For the cellulose diacetate fibres, bath exhaustions at equilibrium are considered. The data suggest that while the hydrophilic beta-D-glucopyranose ring decreases toxicity, it also reduces the substantivity towards hydrophobic fibres. The analogue with an acetylated beta-D-glucopyranose ring has dyeing properties comparable to traditional disperse dyes, and, in effluent treatment, is easily converted by hydrolysis of acetate groups to a non-toxic dye. (C) 2000 Elsevier Science Ltd. All rights reserved.