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

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