Heinrich Zollinger

Porosity Versus Segment Mobility in Dye Diffusion Kinetics— A Differential Treatment: Dyeing of Acrylic Fibers

The diffusion kinetics of the cationic dye thionine from an aqueous buffer solution into the two acrylic fibers Dralon X-100 and Dunova was studied at various temper atures between 59.0°C and 98.5 °C. The two fibers are practically identical with respect to chemical composition. The glass transition temperatures in the dry state (Tg) and in water (TD) are the same within experimental error. They differ physically, however, with respect to overall porosity and pore size distribution. The evaluation of diffusion kinetics as a function of temperature and their comparison with the temperature dependence of free diffusion in water, as well as desorption experiments, demonstrate that the pore model mechanism and the free volume (segment mobility) mechanism operate simultaneously. The first is dominant for the porous fiber Dunova and the second for the less porous fiber Dralon.

A comparison of the absorption spectra of a series of blue disperse dyes with the colorimetric evaluation of their dyeings

Abstract The wavelengths, molar extinction coefficients and band widths of the main absorption bands in the visible spectra of solutions of nine blue disperse dyes are compared with colorimetric data of reflectance spectra of their dyeings on polyester. The colorimetric data are evaluated on the basis of the CIE chromaticity diagram and the psychometric CIELAB method. All but one dye were commercial dyes and the structures of dyes which were not known from the literature were elucidated by elemental analysis, MS, and 1 H- and 13 C-NMR spectroscopy.

Correlations between the neurobiology of colour vision and the psycholinguistics of colour naming

Neurobiological experiments demonstrate that colour sensation is perceived by the brain by processes which, in principle, follow the opponent colour pairs scheme proposed by Hering in 1874. Tests on colour naming in various European, Asian and Central American languages have shown that the opponent scheme is also reflected in psycholinguistics. The linguistic evolution of colour terms proposed by Berlin and Kay (1969) is correlated directly with the ontogenetic development of language in children as elucidated by Jakobson (1941). Colour vision is therefore a suitable field for interdisciplinary investigations of brain processes and linguistics.

Categorical color perception: influence of cultural factors on the differentiation of primary and derived basic color terms in color naming by Japanese children.

Color naming tests with Japanese children (age 12-15) in Yonezawa, Tokyo and Düsseldorf (Germany) demonstrate that the primary basic color terms based on Herings opponent color scheme are not influenced by the increasing Western cultural influence from Yonezawa to Tokyo and to Düsseldorf. The derived color terms for brown, orange and pink hues do appear to be influenced, however. The results support and extend the findings of Uchikawa and Boynton (1987). They verify the hypothesis that the psycholinguistics of color naming are based on a universal neurobiology of human color vision.

Why just turquoise? Remarks on the evolution of color terms

SummaryThe location of the foci of green and blue in the perceptual color solid indicates that there is space for a derived color term between these two hues. Diachronic and synchronic linguistic studies on color term lexica explain that a term for turquoise is likely to develop into a derived basic color term (in the Kay and McDaniel definition), at present in languages of industrialized countries. In addition to the hypothesis of Zimmer (1982) that ‘türkis’ (in German) is the result of universal production system for color terms, cultural, social, and psychological factors influence the evolution of new basic color terms.

Change of Water States in Acrylic Fibers and Their Glass Transition Temperatures by DSC Measurements

DSC measurements of four kinds of acrylic fibers (Dralon X-100, Dunova, Acryl, and Aqualon) were made after equilibration with various amounts of water. The DSC curves in heating from -80° to 20°C were analyzed to obtain information on the state of water in these fibers. The results show that in a water-saturated state, the porous fibers Dunova and Aqualon contain much more free water than the less porous fibers Dralon X-100 and Acryl, while all four fibers contain relatively small amounts of bound water. The effect of water content on the glass transition temperatures Tg of these four fibers was investigated by analyzing the DSC heating curves from 50° to 150°C for fiber/water mixtures. Tg decreases with increasing water content and approaches an almost constant value for all four fibers. Considering the results on the change of water states and the change of Tg models are presented for describing the dye diffusion into porous and less porous acrylic fibers from aqueous dyebath.

Crosslinking Effects in Reactive Dyeing of Protein Fibers

Dyes featuring two reactive groups or one bifunctional group, when applied to wool and silk, can reduce the solubilities of these fibers in appropriate solvent systems. This is consistent with the formation of crosslinks during dyeing. Of the nine dyes studied, the most effective crosslinker possessed two well separated reactive groups. On wool, dyes with more closely located reactive sites were comparable in effect to formaldehyde. The reduced solubility of wool dyed with dyes containing one α-bromoacrylamide group indicates a bifunctional reaction of this group; this is in agreement with a hy pothesis stating bifunctionality. On silk, α-bromoacrylamide dyes undergo bifunctional reactions to a limited extent only, if at all. With other bifunctional dyes, the number and distribution of cnosslinks on silk depend on the type of reactive group and the method of dyeing. The inhibition of dye penetration after crosslink formation on silk in dyeings with a difluorochlo ropyrimidine dye at 40°C can be greatly alleviated by dyeing at 90°C, and thereby distributing the crosslinks more evenly throughout the fiber. The effectiveness of the highly reactive dichlorotriazine system in crosslinking depends on the method of dyeing used on wool and on silk.

Rates of dediazoniations of arenediazonium ions complexed with 18-, 21- and 24-membered crown ethers

Abstract The evaluation of the kinetics of dediazoniation of benzenediazonium tetrafluoroborate and p -chlorobenzenediazonium tetrafluoroborate in 1,2-dichloroethane at 50°C in the presence of 18-crown-6, 21-crown-7 and dicyclohexano-24-crown-8 demonstrates that the rate constant for the dediazoniation within the complex is smallest, and the equilibrium constant for complex formation is largest for the complex with 21-crown-7.

Dye-Fiber Bond Stabilities of Reactive Dyes Containing Phosphonic Acid Groups

Dyes containing phosphonic acid groups as reactive links to be bonded to cellulose hydroxyl groups have been recently introduced into commercial use. In this investigation, the stability of the dye-fiber bond in reactive dyeings of this type on cotton fabrics has been determined by measurement of the rate of hydrolysis in the pH-range 2.2-8.6 at 98°C. The results demonstrate that this class of reactive dyes has dye-fiber bond stabilities that are in the same range as those of the other major classes of reactive dyes investigated previously. The dye-fiber bond stabilities reflect the wet-fastness properties of these dyeings.

Mechanism of azo coupling reactions: Part XXXV1: pH-dependence and Ortho/Para ratio in coupling reactions of aminohydroxynaphthalenesulfonic acids

Abstract We have found that the conclusions made by Freeman et al. [Dyes and Pigments, 7, 215 (1986)] in a recent investigation on the products of diazo coupling reactions with aminohydroxynaphthalenesulfonic acids are not correct. It was previously known that, with these coupling components, in the pH range 5 to 7, substitution takes place in the ring bearing the OH group and a mechanistic explanation of this fact appeared in the literature in 1952. With derivatives of 1-naphthol-3-sulfonic acid, coupling under alkaline conditions takes place preferentially in the 2-position. Literature data demonstrate that the 1 H-NMR signals for the OH protons found by Freeman originate from ortho-hydroxyazo compounds and not from their para-isomers.