PROGRESS IN COLOR, COLORANTS AND COATINGS
Year:2018 | Volume:11 | Issue:2|Papers Count:6

In this study, four arylazobenzylidene dyes (a-d) were synthesized with excellent yields in two steps using Knoevenagel condensation and azocoupling reactions. Absorption spectra of these dyes with different substituents were investigated in organic solvents as a function of solvent polarity. The spectral features of synthesized arylazobenzylidene dyes were described according to azo-hydrazone tautomerism as well as the solvatochromic characteristic of the approved tautomer. The nature and degree of solute-solvent interactions were illustrated using Kamlet-Taft multi-parameter polarity scales. The effects of acid-base on the UV-visible absorption spectra of the dyes were reported. In addition, different absorption characteristics were observed for these dyes in pure diethanolamine. Prog. Color Colorants Coat. 11 (2018), 69-78© Institute for Color Science and Technology.

An ecological approach has been obtained by using natural dyes and mordant for dyeing process. Fabrics were dyed using myrobalan extract as natural mordants and green dye. A red color was obtained by using theses mordants. The color of dyed fabrics was investigated in CIELab (L*, a* and b*) and K/S values. Finally, all dyed fabrics were tested for wash and light fastness properties as per ISO standard test methods. The results of using biomordants for fabrics dyeing were comparable with that of metallic mordants in terms of color strength and fastness properties. Myrobalan extract as biomordant produced red color with medium fastness properties and thus offer full potential to replace metal salts in dyeing process. Prog. Color Colorants Coat. 11 (2018), 79-83© Institute for Color Science and Technology.

In this work, zinc ferrite magnetic and zinc ferrite-graphene oxide nanocomposites were synthesized through a facile hydrothermal method and their absorbing capability for dye removal was studied. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the synthesized nanocomposite. The UV-Vis results showed that the addition of as-prepared magnetic nanoparticles on the graphene oxide sheets significantly improved the adsorption of organic dye pollutants from aqueous solution. Magnetic hysteresis measurements were done on a vibrant sample magnetometer (VSM) viewing the soft paramagnetic property of the resulting products at room temperature. Structural and morphological analyses were also performed in detail. The adsorption kinetics was described by pseudo-second-order model. Zinc ferritegraphene oxide nanocomposite could be recycled suitably and possessed of adsorptive property, so it can be developed as an inexpensive and alternative adsorbent for dye wastewater treatment. Prog. Color Colorants Coat. 11 (2018), 85-92© Institute for Color Science and Technology.

this study is aimed at evaluating the performance of tetrakis[methylene-3-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate] methane (S1010), tris(2, 4-di-tert-butylphenyl) phosphite and ascorbic acid antioxidants in stabilizing hydroxypropyl cellulose. For this purpose, films with weight percent ratio of 0. 4 % (w/w) were prepared in 1 % isopropanol solution (w/v). Then, the films were tested under three accelerated aging conditions, i. e. light (UV; 216hr), dry-heat (120° C; 240 hr) and moist-heat (70° C; RH: 95%; 240 hr). During the aging processes, structural changes were studied using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy based on the defined destruction indices. In addition, color changes of the films were evaluated by colorimetry in CIELab system before and after aging processes. According to the results, S1010 phenolic antioxidant improved color and structural stabilization of HPC against environmental destructing factors in photooxidation, thermooxidation and hydrothermal degradation processes. Prog. Color Colorants Coat. 11 (2018), 93-101© Institute for Color Science and Technology.

Polysulfide is well known elastomer for use in aerospace applications due to providing flexible coating and chemically resistant sealants. In this work, the effects of carbon black content on curing behavior of polysulfide elastomer were investigated and rheological properties for samples with different filler content (15, 20 and 25 phr) were evaluated by rheometric mechanical spectrometer (RMS). According to RMS analysis, sample with 20 phr carbon black had minimum gel point temperature and loss factor and highest elasticity. Also, the time sweep test for the optimal sample resulted from temperature and frequency sweep at 90 ° C was done and gel time obtained less than a few minutes. From the dynamic differential scanning calorimetry (DSC) diagram for polysulfide sample with 20 phr carbon black observed one exothermic peak in heat flow for uncured sample that corresponded to the formation of cross-linking network and curing of polysulfide elastomer. Prog. Color Colorants Coat. 11 (2018), 103-112© Institute for Color Science and Technology.

in this paper, the effect of whiteness attribute of white substrates on blackness property of black coated fabrics is investigated. To this aim, four cotton fabrics with different whiteness and tint attributes are used as white substrates. To prepare a set of black samples, various concentrations of four color pigments, i. e., red, green, blue and yellow, were mixed with the black one and applied on white fabrics via the conventional textile printing method. Then, the colorimetric attributes of black coated fabrics prepared by applying the same recipes on different white substrates were investigated. The results indicated the effect of substrate’ s whiteness index and tint factor on colorimetric characteristics of achieved blacks where by decreasing of the whiteness attribute of white substrates, the black coated fabrics became darker and more saturated. Besides, the tint attributes of black coated fabrics differ dramatically depending on the colorimetric attributes of the white substrate. As a summary, the general imagination of dominant effect of blackness rather than the whiteness attribute of employed white substrate is not approved. Prog. Color Colorants Coat. 11 (2018), 113-122© Institute for Color Science and Technology.