The acid-combining capacity of wool

Combination of wool protein with weak acids

“…The very large extent of combination with wool of such weak acids as formic acid and monochloroacetic acid, in the undissociated form, acquires pa,rticular significance in view of the long-lmown profound influence of these substances on the dyeing, swelling, and the stress-strain characteristics of wool fibers [1]. Similar combination with undissociated acid by dissolved proteins has recently been reported [7].…”

“…Numerous studies have been made of the combination of wool with acids and bases [1,2,3,4,5,6]. 2 With the notable exception of some measurements by Speakman and Stott [1], practically all of these studies have been made with strong acids and bases which are totally dissociated into their constituent ions.…”

“…2 With the notable exception of some measurements by Speakman and Stott [1], practically all of these studies have been made with strong acids and bases which are totally dissociated into their constituent ions. Thus, little is lmown of the effect of the presence of un dissociated acids on the equilibrium between wool and hydrogen ions, or of the relative affinities for wool of the anions of various weak acids.…”

“…Thus, little purpose would be served by attempting to evaluate it by extrapolation/ since the accuracy of the titration data is lower at high concentrations of acid, where only a small fraction combines, and the effects of water absorption by the fibers are greatest [3 , 4]. 5 The values of the quotient (column 7, table 1) at the highest dilution should come closest to expressing the inherent tendency of the acid to combine with or to solvate wool. However, it must be recognized that it is these values which are most subject to error.…”

Electrophoretic studies of wool

“…(See below for values in acetate buffers.) Speakman [9] explains the low value determined by electrophoresis as being caused by the presence of -NH-groups on the surface of the wool. Although we agree that the low value is due to a surface phenomenon, it is hard to see how the kind of groups Speakman postulates could cause a lowering rather than a raising of the pH value at which the wool is isoelectric.…”