Abstract
The dyeability of acrylic fiber “Exlan L” with disperse dyes having different substituted groups was examined at 90°C and 100°C in the states of equilibrium.
The effects of the substituted groups in disperse dyes on their dyeabilities were discussed, using the thermodynamic parameters such as the standard affinity (-Δμ°) the standard heat of dyeing (-ΔH°) and the change in standard entropy (-ΔS°).
It is found that both affinity and heat of dyeing are increased by introducing -NH2 groups or -OH groups into dye molecules.
Consequently, it is considered that polar interaction such as hydrogen bonding contributes to dyeability for acrylic fiber.
On the other hand, non-polar interaction such as Van dar Waal's force also contributes to the dyeability, since both affinity and heat of dyeing are increased by introducing -CH3 groups or -C2H5groups or phenyl groups into dye molecules and by lowering the solubility of the dye in water.
Based on the linear relationship between ΔH° and ΔS° for most of the disperse dyes, it is assumed that the mechanism involved dyeing acrylic fiber does not change with the dye structures or the substituted groups of the dyes, namely that the contribution of both intractions and the steric effects of the fiber structure on the dyes are relatively constant in these cases.
