Abstract
In order to clarify the dyeing mechanism of PVA fiber with reactive dyes, the effect of the amorphous state on the dyeability of reactive dyes was studied. Two reactive dyes were synthesized and the experiments on the dyeabilities were carried out in the homogeneous (solution reaction I) and heterogeneous systems (solid state reaction II).
The results were as follow,
A) The effect of substituent of 1, 3, 5-triazine ring on the rate of the reaction of PVA with reactive dyes depended on its electron density.
B) The reaction rate of II was very slow comparing with I and it was considered that the diffusion of dyes into PVA fiber is determined by the reactivity of PVA fiber because of dye aggregation.
C) The dyeability of PVA fiber depended on the degree of the crystallinity and the orientation. The reaction did not occur at the degrees of crystallinity above 50% and this dyeability increased with the chemical and mechanical treatment of PVA fiber.
It was considered that the causes of this poor dyeability of PVA fiber is related to the surface structure of the fibers and the hydrogen bonding of PVA molecules.
