The low-temperature dyeing kinetics of radiation-grafted poly(ethylene terephthalate) fabric were studied. The effects of the graft yield (GY), dye concentration, and dyeing temperature on the color difference (CD) of methacrylic acid grafted polyester fabric were studied for astrazonrot violet (AV) and rhodamine red (RR) basic dyes. CD increased sharply with an increase in GY and tended to level off at higher degrees of grafting. The best dyeing conditions were achieved for both dyes at pH 11.5. CD of the grafted fabric increased rapidly as the dyeing time increased; this was followed by a relatively slow dyeing rate within a few minutes, which depended on the concentration and temperature of the dye bath. The initial dyeing rates and rate constants for the AV dye were higher than those for the RR dye. The dyeing process followed 0.14-order kinetics and was independent of the dyeing temperature or the type of dye. The dyeing rates and rate constants increased with an increase in the dyeing temperature. An Arrhenius-type plot of the natural logarithm of the dyeing rate constant versus the inverse of the absolute temperature yielded apparent activation energies of 4.9 and 13.8 kJ/mol and pre-exponential rate constants of 9.4 and 100.6 (CD/GY)s(-1) for the AV and RR dyes, respectively. The mechanism of the dyeing process for the two dyes was diffusion-controlled, and their dyeing rates depended on the type of basic dye. (C) 2004 Wiley Periodicals, Inc.