Abstract
In order to improve the wet fastness of nylon dyed with acid dyes, after-treatment by tannic acid (T. acid) and antimony potassium tartrate (APT) have often been carried out. The mechanism of fixation of T. acid with APT is still unknown.
In this paper the interaction between T. acid and APT in aqueous solution was investigated spectrophotometrically.
Results obtained are as follows:
(1) Two isosbestic points (254nm, 290nm) were found in absorption spectra of aqueous solution of T. acid and APT mixture.
(2) It was found that 1:1 complex was formed by reaction of two components in aqueous solution.
(3) The values of free energy (ΔF°), entalpy (ΔH°) and entropy (ΔS°) change for the complex formation were respectively-8.1_??_-8.4 kcal/mol (5_??_40°C), -13.3 kcal/mol and -17.4 e. u.
