INTRODUCTION OF CHELATE BOND TO FIBER

Abstract

In order to know the effect of chelate formation with Hg on the dyeing properties of wool, the energy of activation in the absorption of dyes by Hg treated wool is determined. The same process as in the case of the absorption of Hg with wool is employed. The dyeing process is considered to be divided into the following three steps (a) absorption of dyes on the surface of fiber, (b) the diffusion of the adsorbed dyes at the surface of fiber into the inner part of fiber, (c) chemical combination of dyes with metallic ions in fiber. The following relationship is found appliciable in this case:Where, x is reaction rate (the quantity of dyes absorbed by wool in a state is divided by the quantity of dyes absorbed at equibrium), t is time.It means that the diffusion of dyes in fiber is a rate determining step in this dyeing. From the above equation (1), (2) is obtained, andThe energy of activation is calculated from (4) belows, From the inclination of these straight lines and from the difference between log xt20 and log xt30, and between log xt30 and log xt50, the energy of activation is computed. Acid orange II, acidic dyes, and chrome methyl orange A, mordant dyes, are used.The energy of activation of the absorption of these dyes with the Hg treated wool was compared with that with non treated wool. For non-treated wool, E were found to be 7570 cal/mol between 20 and 30°C, and 9830 cal/mol between 30 and 50°C, for Acid orange II and 11800 cal/mol (20_??_30°C), 11150 cal/mol (30_??_50°C) for chrome orange A. For Hg treated wool, E were 10720_??_13500 cal/mol (20_??_30°C) and 19900 cal/mol (30_??_50°C) for Acid orange II, and 26000 cal/mol (20_??_30°C) and 22000 cal/mol (30_??_50°C) for Chrome Orange A.Using the above dyes, Hg treated wool needs much more energy than non-treated wool does.Cross linking formed during the chelation with Hg in wool and the change of the charge in wool may have some relations to the above results.