J. D. Leeder

24—STOICHIOMETRIC ANALYSIS OF THE WOOL-WATER ISOTHERM

Determination of the amount of absorbed water attributable to the various types of side-chain polar groups in wool keratin at humidities of up to 80% r.h. enables a stoichiometric analysis of the wool-water isotherm to be made. The amount absorbed by the aromatic (tyrosine) hydroxyl and aliphatic (serine and threonine) hydroxyl groups was estimated from the change in the water-absorption isotherm after separate chemical modification of these groups. The reduction in water content was much less than that for either amino-group or carboxyl-group modification, the data for these having been reported previously for wool from the same source examined under identical conditions. The difference between the sum of the water attributable to the side-chain basic, carboxyl, and hydroxyl groups, and the water content of unmodified wool has been designated as water attached to peptide and amide groups. The water-sorbing power of these groups is in good agreement with experimental data for peptide groups in polyglycine...

10—THE WRINKLING BEHAVIOUR OF WOOL FABRICS: THE EFFECT OF ANNEALING AND CROSS-LINKING

An investigation is described in which various polyfunctional compounds were applied to wool in attempts to stabilize the temporary improvements in wrinkle-recovery brought about by ‘annealing’. Several reactive systems involving formaldehyde were found to produce the desired permanently improved wrinkle-recovery.

5—THE WRINKLING BEHAVIOUR OF WOOL FABRICS: THE TREATMENT OF ANNEALED WOOL WITH RESORCINOL–FORMALDEHYDE POLYMERS

An investigation is reported in which resorcinol–formaldehyde resin treatments were used with annealing to improve the wrinkle-recovery of wool fabrics. Whereas the effects of the individual treatments were additive, the resin appeared to inhibit the annealing and deannealing processes in the wool. A concurrent annealing–resin-forming treatment gave better results than a sequential treatment (in which the resin was formed before the annealing operation)at the same weight of added polymer. However, the reasons for this difference could not be fully determined.

56—THE WRINKLING BEHAVIOUR OF WOOL FABRICS: THE EFFECT OF THE STRUCTURE OF FORMALDEHYDE CONDENSATION POLYMERS ON THE STABILIZATION OF ANNEALED WOOL

An investigation is reported of the use of formaldehyde condensation polymers of aromatic amines, heterocyclic amines, and phenols to stabilize the improved wrinkle-recovery of annealed wool. These polymers were formed in situ during the annealing process. The most effective polymer networks were those obtained from the reaction of formaldehyde with multifunctional compounds such as (i) 2,4,6-triaminopyrimidine, (ii) 2,6-diaminopyridine, (iii) 3,5-diamino-1,2,4-triazole, (iv) 1,3,5-trihydroxybenzene, (v) 1,3-dihydroxybenzene, and (vi) 2,4,6-triamino-s-triazine.

43—THE WRINKLING BEHAVIOUR OF WOOL FABRICS: THE EFFECT OF METAL SALTS ON DRY AND WET WRINKLE-RECOVERY

The dry and wet wrinkle-recovery of wool fabrics can be improved by reaction with metal salts in the anionic or cationic form. Small amounts of substantive metals are shown to have produced significant improvements in wet wrinkle-recovery, but, with the exception of chromium, only relatively large amounts of metals such as mercury, uranium, tungsten, and molybdenum improved dry wrinkle-recovery. The mechanism by which mercuric acetate improves dry wrinkling does not appear to involve sulphur, despite extensive reaction between mercury salts and sulphur-containing residues, such as cysteine, cystine, and cysteic acid.

73—WOOL–POLYMER SYSTEMS : THE EFFECT OF THE INTERNAL DEPOSITION OF POLYMERS ON THE WRINKLE-RECOVERY OF WOOL

Experiments are described in which various polymers were polymerized inside wool fibres and their effects on the wrinkle-recovery of treated fabrics evaluated. Linear polymers were found to markedly decrease the wrinkle-recovery, and cross-linked vinyl and acrylic polymers produced only small improvements. Formaldehyde condensation polymers formed in and on the wool in aqueous solution produced significant improvements, but much larger improvements were obtained when these polymers were formed under annealing conditions.