A novel synthesis, characterization and application of an anionic Cr-complexed azo dye based on environmental considerations

Abstract

A simplified novel one pot method of synthesis of a Cr-complex anionic azo dye and the subsequent minimization of the Cr-content in the final dye by ultrafiltration was carried out. Ultrafiltration allows the production of highly concentrated purified metal-complex dyes with drastically reduced free metal and electrolyte content. All dyes were characterized by FT-IR, UV-Vis, NMR and their melting points. X-ray fluorescence analysis and atomic absorption measurements were performed for the determination of free and total Cr-content for the synthesized metal-complex dye before and after ultrafiltration. All of the synthesized dyes (before and after ultrafiltration) were applied for the dyeing of wool and polyamide fibres, and colour measurements and fastness property tests were carried out. The wash and light fastness properties of the dyeings were excellent for the metal-complex dyes, but inferior for the non-metallized dye.

Synthesis, characterization and application of anionic metal complex azo dyes as potential substitutes for Cr-complex dyes

“…This is in agreement with previous findings. 15,25,32,33 The synthesized metal complex dyes I. (1-5) were passed through the ultra-filtration unit housed with a PCI ES404 polyethersulfone-type membrane.…”

“…This paper is a continuation of our previous work on the simplified novel one-pot synthesis of a Cr-complex azo dye, as well as the Co-complex and Fe-complex acid azo dyes and the minimization of free metal and electrolyte content by ultra-filtration. 15,25 Apart from the main environmental benefit of the implementation of ultra-filtration technology (since on the one hand we have elimination of toxic metals present in the dye and additionally the total elimination of the solvents in the liquid dye formulations), this technology results also in financial benefits since the high-strength dyes produced due to elimination of inorganic salts reduce packaging and transport costs significantly. The cost benefit of ultra-filtrated metal complex liquid dye formulation is more than 30%.…”

Synthesis, characterization and ultrafiltration of reactive dyes. Application by exhaustion and/or ink-jet printing—II

“…The procedure was repeated for many concentrations of the dyes to find their maximum level of solubility. 15 Quantitative determination of K + , Na + , SO 4 ¼ , and Cl -ions…”

“…Conductivity measurements were performed using a Crison Conductimeter Basic 30, Crison, Barcelona, Spain) and pH measurements were made using a WTW Microprocessor 535 pH meter (Los Angeles, USA); viscosity measurements were made using a Viscostar plus+ H (Fungilab, Barcelona, Spain) viscometer. The above properties were measured at room temperature and atmospheric pressure for1,4,8,11,14, 30, 60, and 90 days.…”

Synthesis, Characterization and Ultra filtration of Reactive Dyes. Application by Exhaustion and/or Ink-Jet Printing. III

“…Due to the covalent bond formed between the dye molecule and the reactive group of the fibre reactive dyes have good fastness properties and are commonly used in dyeing those fibres mainly cellulosic fibres like cotton [1][2][3]. In continuation of previous work on the synthesis of azo dyes and their purification by using membrane technology (ultrafiltration) [4][5][6] three new azo reactive dyes of different metallic salt (Na, K, Li) were synthesized in this work. The dyes were purified-concentrated by ultrafiltration technology, characterized and applied on cotton, wool and nylon 66 fabric by exhaustion (dyeing) and ink-jet printing.…”