Abstract
It was previously reported by us1, 2) that the effects of polymer solution in direct dyeing consisted of (1) adsorption effect by polymer, and (2) cation effect (when polymer-electrolyte).
In this paper, the decrease of dye-amount, adsorbed by cellulose is discussed from the view points of adsorptinon of dye by polymer (wheat starch) and the temperature depending on it.
The results are;
(1) An addition of starch to dyebath reduces the amount of dye adsorbed by cellulose and therefor apparent affinity of dye.
(2) It is assumed that these decrease are due to the large affinity of starch for direct dye and adsorption of dye by starch, and decrease of the effective dyebath concentration.
(3) On these assumptions, the effective dyebath concentration [D]σ′ and the difference between the apparent conc. [D]σ and [D]σ′, which corresponds to the amount of dye adsorbed by starch, are calculated. It is shown that there exists the following relation; That is to say, adsorption by starch obeys the distribution law.
(4) From the temperature dependence of distribution coefficient K, the heat of adsorption of dye for starch are calculated. The value obtained (12 kcal/mol for Direct Scarlet B and 11kcal/mol for Chrysophenine G) are somewhat smaller than the heat of dyeing for cellulose (17kcal/mol and 15kcal/mol, respectively).
