Wool Substrate Research Articles

Reaction of Cystine Residues in Wool with Peroxy Compounds

Wool was oxidized under aqueous acidic conditions with Caro's salt, and the oxi dation products of cystine were measured using Fourier transform infrared spectroscopy coupled with the attenuated total internal reflectance sampling technique. The reso lution of the infrared bands in the wool spectrum was improved by differentiation to the second-order derivative. Following differentiation, individual sulphur-oxygen bands in the infrared spectrum of wool were resolved and identified. The intensity of the cysteic acid band was proportional to cysteic acid concentration, and following such oxidation treatments of the wool substrate, cysteic acid was the main oxidation product formed from cystine. The overall effect of applying Caro's salt to wool was determined by high performance liquid chromatography. The amino acids were labeled with the fluorescent tag, 9-fluorenylmethyl-chloroformate, separated on a C-18 column, and detected at 340 nm. The results show that permonosulphuric acid treatments convert cystine to cysteic acid and methionine to methionine sulphoxide and reduce the con centration of tyrosine in wool.

Production of keratinolytic enzymes in a rotating frame bioreactor

The keratin-degrading actinomycete Streptomyces fradiae was cultured in a bioreactor of novel design in which the wool substrate was wound over a supporting frame partially immersed in salts medium and slowly rotated during the course of fermentation. Both disulphide reductase and keratinase enzyme activities were detected in culture supernatants and the substrate was almost totally solubilized.

Electron Beam-Induced Graft Polymerization of an Oligomeric Vinyl Phosphonate on Wool

Electron beam-induced graft polymerization of the oligomeric vinyl phosphonate, Fyrol 76, and/or comonomers on wool substrate was studied using 0.5 to 10 Mrad irradiation doses. Polymerization was retarded by the presence of oxygen and moisture, and in all experiments the rate of polymerization slowed above 2 Mrad dose. Increasing concen trations of Fyrol and hydrogen donors on the wool minimized the effect of oxygen on polymerization. Comonomers had little effect on grafting of Fyrol but did decrease the degree of flame retardancy achieved compared to grafting of Fyrol alone. Wool with uptakes of greater than 5% polymerized Fyrol exhibited improved flame-retardant properties without significant loss in physical and esthetic properties.

Copolymers of Wool Keratin: Sorption Properties

Abstract The internal deposition of polymers in wool fibers forms copolymers with modified sorption properties. Water vapor sorption isotherms of some copolymers are presented to illustrate the influence of the properties of the added polymer and the effects of interactions between the polymer and the wool substrate. Changes in water content are not proportional over the whole isotherm and it is shown that polymerization causes changes in the state of the water in wool. The kinetics of water sorption show little change at low humidities but absorption into copolymers is markedly slower at intermediate and higher humidities. The mode of initiation of polymerization has little effect on the sorption properties of the copolymer. Grafting, compared to internal deposition without covalent bonding, does not influence sorption behavior unless cross-links are formed and these cause a marked reduction in formic acid swelling. The influence of sorption properties on the observed physical properties of wool copolymers is discussed.

Radiation-Initiated Polymerization in Aged Wool Keratin

Abstract A mutual irradiation technique for polymerization from the vapor phase has been used to internally deposit a number of polymers in wool. Prior to the polymerization step wool samples were aged by conditioning at 80°C in the presence of monomer and water vapors. This treatment modified the tensile properties of the wool; producing stronger fibers with a reduced stress relaxation. These changes can be reversed by saturation with water. The irradiation levels used were not sufficient to modify the changes produced by aging. Polymerization from the vapor phase enabled copolymers to be formed without disturbing the aged state of the wool substrate. The sorption and tensile properties of the copolymers have been examined and it appears that the effects of aging are retained by a wool-poly(methyl methacry late) copolymer even after relaxation in water.

The Effect of Wool on the Photolysis of a Model Stilbene Fluorescent Brightener

The effect of suspended wool on the photodecomposition of a model fluorescent brightener, disodium 4,4'-diacetamido stilbene-2,2-disulfonate in aqueous solutions has been studied. Low concentrations of suspended wool increase the rate of brightener photodecomposition, whereas higher wool concentrations retard the rate of brightener decomposition. Photo-oxidation of the brightener in solution or on wool substrate gives the same major photocleavage product, sodium 5-acetamido-2-formylbenxenesutfonale.

Color Changes in Wool During Processing

Color is an important physical property of wool fibers which can be defined with the aid of color- measuring instruments. The color of a fiber is a limiting factor in the range of shades into which the fiber can be dyed. Color changes which occur to the wool substrate itself during normal proc essing steps, such as scouring, carbonizing, bleaching, dyeing, steaming, drying, and others, are sig nificant in terms of the resulting limitations imposed on the shades obtainable. 'I'he size of the re flectance-level changes occurring in these processes is given and related to changes in utility and value of the fiber.