Acid Dyestuffs Research Articles

Physical properties and dyeability of NaOH‐treated silk fibers

AbstractDomestic (Bombyx mori) and wild (tussah, Antheraea pernyi) silk fabrics were treated with diluted NaOH solutions by the pad/batch method. The equillbrium moisture regain of tussah silk fibers increased steadily with alkaline treatment, while that of B. mori did not change. B. mori tensile strenght and elongation at break were slightly impaired. The average molecular orientation and crystallinity of both kinds of silk remained unchanged. Differential scanning calorimetry (DSC) and thermomechanical analysis(TMA) showed that the thermal behavior of B. mori silk was almost unaffected, while that of tussah exhibited slight changes in the temperature range 250–300°C. By dynamic mechanical measurements (DMA) it was elucidated that both storage and loss moduli of B. mori silk fibers decreased following NaOH treatment. On the other hand, tussah silk exhibited a noticeable upward shift of the major loss peak. Alkali‐treated tussah silk fibers, dyed with an acid dyestuff, attained a lower degree of dye‐bath exhaustion. © 1995 John Wiley & Sons, Inc.

Peat as an adsorbent for dyestuffs and metals in wastewater

The ability of peat to adsorb dyestuffs and metals from wastewaters was investigated. Equilibrium isotherms were determined in order to assess the maximum adsorption capacity of some basic and acidic dyestuffs, and metal ions onto peat, lignite and other adsorbents. Economic evaluations indicated that peat was a particularly attractive adsorbent. Kinetic studies for the adsorption of basic dyes onto peat were undertaken in agitated batch and fixed bed adsorbers. Mass transport models detailed elsewhere were tested and used to predict (a) the concentration decay curve for batch adsorption and (b) the breakthrough curves in fixed bed adsorption. The models tested were single-resistance models and included an estimation of the external mass transfer coefficients.

Equilibrium Studies during the Adsorption of Acid Dyestuffs onto Maize Cob

The adsorption of acid dyestuffs in solution onto maize cob has been investigated. Equilibrium isotherms have been determined for the adsopriton of Acid Blue 25 (AB 25) and Acid Red 114 (AR 114) onto maize cob. The L-shaped adsorption isotherms suggest that adsorption proceeds through ionic bonding and that the dye molecules are adsorbed in a flatwise manner on the surface of the maize cob particles. The maximum adsorption capacity of the maize cob was found to be 47.7 and 41.4 mg dye per g maize cob for AR 114 and AB 25, respectively.

Colour removal from textile effluents by adsorption techniques

The adsorption of two basic dyestuffs (Atrazon Blue and Maxilon Red) and two acid dyestuffs (Telon Blue and Erionyl Red) onto maize cob was studied. High adsorptive capacities were observed for the adsorption of basic dyestuffs, namely, 160 and 94.5 mg dye per g maize cob for Astrazon Blue and Maxilon Red, respectively. Lower capacities were obtained with the acid dyestuffs, namely, 47.7 and 41.4 mg dye per g maize cob for Erionyl Red and Telon Blue, respectively. A series of contact-time experiments was undertaken in an agitated batch adsorber to assess the effect of the system variables, namely, agitation speed, maize cob particle size and maize cob mass. The experimental results for these contact-time experiments were discussed.

Modifiers improving the dyeability of polypropylene

AbstractA number of copolymers on the basis of acrylate or methacrylate copolymers containing nitrogen and of ethylene copolymers containing structural units of N, N‐diethyl‐2‐aminoethyl acrylate and 2,2,6,6‐tetramethyl‐4‐piperidyl acrylate or of the vinyl ester of N, N‐dimethyl‐ε‐aminocaproic acid were synthetized. These copolymers were added to polypropylene before spinning. The dyeability of stretched fibres with acid dyestuffs was evaluated.

Synthesis of dyes from 1-amino-2,4-dichloroanthraquinone

A method for the synthesis of 1-amino-2,4-dichloroanthraquinone of very high purity is described, involving chlorination with gaseous chlorine of 1-aminoanthraquinone in boiling aliphatic organic solvents. The 1-amino-2,4-dichloroanthraquinone thus obtained was used in the synthesis of blue acid dyestuffs by condensation with various arylamines, followed by sulfonation with oleum. The resulting dyes had similar spectrophotometric and application properties to those of the analogous derivatives of 1-amino-2,4-dibromoanthraquinone.

The aggregative effect of acid dyestuff (orange II) on the activation energy of wool dyeing

Abstract In dye liquor, the hydrophobic group of acid dyestuff molecules often interacts with one another to form aggregates. For the purpose of investigating the aggregative effect of acid dyestuff on the activation energy of wool dyeing, this study derives a rate equation based on the theory of Langmuir chemisorption and deals with the activation energy of wool dyeing under different dyeing temperatures and dyestuff concentrations. The Arrhenius plot from the rate of different dyeing temperatures clearly indicates two straight lines which intersect at 60°C. It is clear that the activation energy found at temperatures below 60°C is higher than that at temperatures above 60°C. It is suggested that when temperatures are below 60°C, the acid dyestuff molecules are in an aggregated state, so that the activation energy below 60°C is higher than that above 60°C. It is also suggested that the higher the concentration, the higher will be the activation energy.

Concurrent dyeing and finishing: V. One-bath dyeing and easy-care finishing of cotton fabrics with acid dyestuffs and N-methylol compounds using different catalytic systems

A number of catalysts have been used for effecting concurrent dyeing and easy-care finishing of cotton fabric with acid dyes and N-methylol finishing agents. Factors affecting the process, such as the nature and concentration of catalyst, the finishing agent, the additive and the dye as well as curing temperature, were investigated. Evaluation of the simultaneously dyed and finished fabric was made with respect to colour strength, wrinkle recovery and fastness properties. The results obtained indicate that, of the eleven catalysts used, ammonium persulphate is the best for effecting concurrent dyeing and finishing of cotton fabric using acid dye and dimethyloldihydroxyethylene urea (DMDHEU).

Novel digital methods for the qualitative characterisation of some acid dyes applied to wool and nylon

The identification of dyes on textile fibres by assessment of reflectance curves is difficult owing to the dependence of spectral reflectance on concentration and spectral interference due to the base colour of the substrate itself. A method of analysis is proposed in which concentration effects are reduced or eliminated by the use of log (K/S) spectra, a function that is analogous to log(absorbance) as classically used in solution studies.Differentiation of the log(K/S) spectrum suppresses interferences arising from the broad background absorption of the fibre, so that the resulting profile generated is a property of the dyestuff alone. The wavelengths at which peaks, troughs and zero crossings are observed may be used to characterise the dyestuff itself. The method possesses greater sensitivity than conventional spectral reflectance or K/S curve analysis. Although the proposed method has been found to have limited utility in distinguishing between closely related acid red dyestuffs that possess almost identical light-absorbing properties, it does afford a rapid and convenient method for characterising acid dyestuffs on wool and nylon fibres.

Some relations beetween chemical Structure and Light Fastness of Monoazo Dispersed Dyes. II

AbstractIn conformity with the assumption that light fastness depends upon the electron density of the azo centre, it is now shown that condensation of the aldehyde function in p‐aryl azo salicylaldehydes with hydroxylamine, semicarbazide, aniline, phenylhydrazine, 2,4‐dinitrophenylhydrazine and ethylene diamine causes in most cases an increase in light fastness on nylon 6 as a result of the decreased electron attracting properties of the functions as compared with the aldehyde function. Aftertreatment of dyeings from arylazo salicylaldehydes or arylazo acetophenone with ethylene diamine causes a similar increase. Further confirmation of this observation is obtained in case of monoazo dyestuffs derived from salicylaldehyde and derivatives which contain the sulphonic acid group when applied as acid dyestuffs on Nylon 6. Application of the latter dyes on wool revealed an analogous tendency only in case of dyes derived from 2‐naphthylamine‐4, 8‐disulphonic acid.

STUDIES ON THE DYEING PROPERTIES OF NYLON 6 FIBER

The relationship between the adsorption of acid dyestuffs on nylon 6 fiber and the chemical structure was investigated by the use of following five kinds of dye; Dye (1) (C. I. Acid Orange 7), Dye (2) (Blue 45), Dye (3) (Blue 120), Dye (4) (Red 99), Dye (5) (Orange 45).Three kinds of nylon 6 fiber which includes amino end group of 9.5×10-5, 5.4×10-4 or 2.5×10-5mol/g, were dyed at 90°C and at pH 3.5.The result was as follows; the adsorption of Dye (1) which had small molecular weight and short molecular chain was completely equal to amino end-group content of the fiber.The saturation of Dye (2) which had the same small molecular weight and short molecular chain as that of Dye (1), was 1/3-1/2 of amino end-group content of the fiber.The saturation of Dye (3) and (5) which had large molecular weight and long molecular chain was lower than the end-group content.The adsorption of Dye (4) which has large molecular weight and long chain showed H type curve.Summary; it is confirmed that the adsorption of dyeson nylon 6 in equilibrium had no linear correlation with the molecular weight and chain length of dyes.

Steam and heat setting of nylon 6 fiber. II. Effects of heat setting of nylon 6 fiber on dyeability and fine structure

Drawn and undrawn nylon 6 fibers subjected to dry heat setting or steam setting were dyed with an acid dyestuff and a direct dyestuff. The dye uptake of these fibers was determined, and the rate of diffusion of a disperse dyestuff was evaluated by the method of Kramer. For the drawn nylon 6, the dye uptake and the diffusion coefficient are generally increased by the steam setting. This tendency increases with the temperature of the steam setting. However, dry heat setting up to about 160°C. gives the reverse tendency. In both types of setting treatments, the diffusion coefficient decreases with increasing tension of the sample during setting. For the undrawn nylon 6, the same effects of the heat setting are observed. Therefore the change of dyeability on steam setting is not attributable to a decrease in the orientation of crystallites but is caused by loosening of the molecular packing in the amorphous region as a result of inclusion of water. The change of dyeability resulting from dry heat setting, however, results from the increase in crystallinity and also closeness of packing in the amorphous regions.

The effect of X-radiation on fumarase activity during different stages of cell division in Tetrahymena pyriformis GL

1. 1. Tetrahymena pyriformis GL was grown in a two per cent solution of proteose peptone. 2. 2. Synchronous division was induced by the temperature flux method. 3. 3. The fumarase activity was tested at different stages of cell division in irradiated and non-irradiated cultures. 4. 4. There was a significant ( P < 0.05) difference in fumarase activity in all cases between the irradiated and non-irradiated determinations. 5. 5. A comparison of the enzymatic activity in the controls of each stage with the activity of the stages immediately preceding and following showed a significant ( P < 0.05) difference in all cases with the exception of the step from stage III to stage V. 6. 6. A comparison of the enzymatic activity in the experimentals of each stage with the activity of the stages immediately preceding and following showed a significant ( P < 0.05) difference in all cases. 7. 7. Ionizing radiation was found to inhibit fumarase activity. 8. 8. The highest rate of enzyme activity was found in the interphase stage of cell division. 9. 9. This acceleration of enzymatic activity is thought to be the result of an attempt of the organisms to replenish the energy needed to carry on the processes of cell division. 10. 10. The enzymatic activity was increased by the addition of phosphate ions. 11. 11. Basic and acid dyestuffs had toxic effects on the enzyme. 12. 12. An enlargement of the cells following exposure to ionizing radiation was noted.

STUDIES ON THE POLYVINYL ALCOHOL FIBERS

Studies were carried out on the relation between manufacturing conditions of the fibers made of modified polyvinyl alcohol partially dimethylaminoacetalized in powder form and their dyeability. The partially dimethylaminoacetalized polyvinyl alcohols were mixed with polyvinyl alcohol and dry spun. With these fibers, the dyeability was tested.It is found that the dyeability of the fibers by acid dyestuffs depends not only on the degree of dimethylaminoacetalization of the samples, but on the draw ratio and the heat-treatment temperature. of the fibers. Consequently, the dyeability is considered to be affected by the number of the sites for dyestuffs and the structure of the fiber. However, these fibers were not so much affected the dyeability by the change in formalization condition in spite of the usual fact that the dyeability of the conventional polyvinyl alcohol by direct, acid and dispersed dyestuffs is quite affected by the formalization conditions. So it is advantageous industrially to use partially dimethylaminoacetalized polyvinyl alcohol as material for dry spinning.

STUDIES ON POLYVINYL ALCOHOL FIBERS

Studies were made on the partial aminoacetalization of polyvinyl alcohol in powder form and dry spun fibers prepared therefrom. Discoloration of the dry spun fibers was observed during the initial stage of the work. This was found to be dependent upon the method of purification or washing of the polyvinyl alcohol. Such discoloration could be effectively prevented by neutralizing the combined acid in the polyvinyl alcohol and adding color stabilizing agents. Further observations indicated that the degree of neutralization of the combined acid was quantitatively related to the degree of discoloration of the fibers during heat treatment. Dry spinning of partially aminoacetalized polyvinyl alcohol presented no problem and the properties of the fibers were similar to those spun from ordinary polyvinyl alcohol as the substituted aminoacetal groups do not disturb crystallization during heat treatment. The fibers is also found to exhibit excellent dye affinity to acid dyestuffs.

AMIDOXIMATION OF PARTIALLY CYANOETHYLATED COTTON FABRIC

Researches on the amidoximation of N % 3_??_5 partially cyanoethylated cotton fabric with the aqueous NH2OH•HCl solution were carried out, including the effects of temperature and pH of reaction bath, concentration of NH2OH • HCl NH2OH/CN mol ratio and addition of nonionic surface active agent on the rate of amidoximation and the mechanical properties of the treated fabric. The results obtained are as following:For amidoximation, the neutral or minute alkaline solution of NH2OH and the temperature of 80°C and above are the necessary. The addition of nonionic active agent gives little retarding effect on the rate of amidoximation. Above and below about 15 of NH2OH/CN mol ratio, the relation of the first and the second order reaction is approximately applied respectively. The discolouration from pale blue to yellowish pale brown with the increase of the amidoximation takes place, while the discolouration of the lower amidoximation is small.By the amidoximation, especially the lower amidoximation of lower cyanoethylated cotton and the slower raising of reaction temperature, the crease and flex abrasion resistance as well as moisture regain increase considerably, retaining the most part of the tensile strength, elongation, tearing strength and softness of untreated fabrics. Generally, even the lower degree of amidoximation gives a striking increase of the acid dyestuff affinity and a great decrease of the basic dyestuff affinity. However, the affinity for the acid dyestuff “Eosine” is lost by the amidoximation.

AMIDOXIMATION OF PARTIALLY CYANOETHYLATED POLYVINYL ALCOHOL FIBER

The amidoximation of the partially cyanoethylated polyvinyl alcoool fiber was carried out in the aqueous NH2 OH HCl solution containing Na2SO4 (20%). The most suitable conditions were pH 7_??_9, NH2OH/CN mol ratio 10, reaction temperature 100°C, and reaction time 1_??_2 hr.Using the partially cyanoethylated PVA fiber (several % of cynoethylation degree), the amidoximated fiber showed the following characteristics. Properties.1. In the formalization for purpose of giving the shrinkproof in boiling water, the concentration of H2SO4 is able to let down about 10%.2. The elastic recovery of the amidoximated and then formalized fiber was remarkably improved especially at the range of lower elongation without much loss of tensile strength. This effect was suggested to be due to an intermolecular cross-linking produced between the amidoxime groups.3. The affinity for the acid dyestuff of the treated fiber was very high. The affinities for basic, Vat and disperse dyestuffs were also higher than that of PVA and cyanoethylated fiber.

口腔粘膜の吸収能力に就いて

1) An attempt to make an artificial cyst of oral mucous membrane was succeeded in Hamster. After narcotizing by Ouropan-Soda, the cheek pouch of the Hamster was pulled out and disinfected. Then, the neck of the cheek pouch was thread in parallel at two points. The surface layer of the mucosa between two threads was cut in a ring, and it was separated rated from the submucosa. Since then, the end of the cheek pouch was replaced as it wasand sewed up. Consequently the end portion of the cheek pouch becomes an isolated cyst.By utilizing above-mentioned artificial cyst, the author made an experiment on absorption power of oral mucous membrane as follows.2) The mucous membrane appeared to be not absorbable to trypan blue when the mixed solution of saturated sodium Bicarbonate, hyaluronidase and trypan blue, a lipoidd unsoluble acid dyestuff, was injected into the artificial cyst.3) The radioactive phosphorus P32 (15μc) was injected into the artifical cyst andft radioactivity of every viscera was calculated by means of Geiger-Mueller Counter. As the results obtained, radioactivity could be recognized and P32 was proved to have been absorbed from the mucous membrane in every viscera of every Hamster in 4 hours after injection.

Prediction of the Color of Dye Mixtures on Textiles

The relationship between the ratio K/S and reflectance as derived by Kubelka and Munk has frequently been used for analytical work, but little attempt has been made to evaluate the accuracy of its application in calorimetric terms. This evaluation has now been made for dyeings by comparing the predicted color with that actually obtained in textile dyeings, and the difference has been expressed in terms of Munsell notation. In this manner the accuracy of the method has been examined for acid, chromed, and metalized dyestuffs on wool, for “acetate” dyes, and for direct and vat dyes on cotton. We find the accuracy of color prediction for acid dyestuffs on wool to average ±0.5 hue step ±0.1 value step, and ±0.4 chroma step. Predictions for the other applications are nearly as accurate except in those cases where interaction of dyestuff molecules occurs.

On the Permeability of Oral Mucous Membrane for a Lipoid Unsoluble Acid Dyestuff, Trypan Blue

The experiment was carried out by dropping solutions of trypan blue, a lipoid unsoluble acid dyestuff, on the oral mucous membrane of mice and observing how it invades into the subepithelial tissue.1. The first experiment was carried out by dropping for 1 hour the 0.5% dye soiutiln, resulting in staining only the upper layer of the epithelium. The second test was tried by dropping for 1 hour the solution containg 0.5% hydrochloric acid or half saturated with bicarbonate of soda, causing the staing of the subepithelial connective tissue, whereas the half an hour's dropping of the solution containing 10% of the hyaluronidase-preparation demonstrated the same result as the second test showed.In case of deep staining connective tissues, almost all tissue elementes such as connective tissue fibres, fibrocytes, walls of cappilaries and muscular fibres are stained evenly. The dye which staines the walls of the blood vessels also seems to run into the blood stream.2. The hydrochloric acid which was added to the the dye solution injured the epithelium, the added bicarbonate of soda and hyaluronidase caused a reduction of the viscosity of mucus, and made the diffusion of the dyestuff easier.3. The walls of the ducts of oral glands are relatively more easily passed by trypan blue. This indicates these parts to be a locus minoris resistentiae for the invasion of virus, bacilli etc.4. The oral mucous membrane of mice, so far as it is normal and intact will never permit the passing of lipoid unosluble molecules and particles of 2-5mμ diameter. Therefore in its normal state, no virus can presumably pass it, but provided the mucus covering is removed or resolved, a danger of virus passing it is increases.