Synthesis of Azo Disperse Dyes with High Absorption for Efficient Polyethylene Terephthalate Dyeing Performances in Supercritical Carbon Dioxide

Abstract

Supercritical carbon dioxide dyeing (SCDD) not only enables strong dyeing performance for a versatile range of polymer material but is also regarded as a green chemical media due to its low environmental impact as well as low risk of product denaturation. Over the decades, azo disperse dyes have been revealed to be efficient dyes and represent the wide majority of dyeing material. Azo dyes possess a wide variety of functional groups to optimize dye synthesis and tune the light absorption properties. Using SCDD, end-chain of different lengths, and functional group exhibiting various electronic affinity, six disperse red azo dyes were synthesized to investigate dyeing performances as woven fabric type, color strain, and color fastness after dyeing are discussed. Dye structure synthesized through a coupling reaction was confirmed by 1H NMR and mass spectroscopy. We found that the light absorption wavelength and absorption coefficient value variation are associated to the nature of the functional group. From the color strength values of the polyethylene terephthalate woven after dyeing, we find that the fiber host and dye dopant chemical structure greatly influence the dyeing process by providing enhanced woven, color strain, and color fastness. In comparison with commercial products, our approach not only improves the dyeing process but also guarantees a strong resistance of the dyed product against water, detergent, perspiration, abrasion, and friction.

Red Disperse Azo Dye Side Chains Influence on Polyethylene Terephthalate Dyeing Performances in Supercritical Carbon Dioxide Media

“…It is commonly admitted that the coupling process occurs under acidic conditions to increase the dye stability, as well as at a temperature of 0-5 • C to maintain the diazonium salt stability [3,38]. Furthermore, the choice of the functional group of the diazonium salt aromatic rings influence the rate of the coupling reaction in which a strong electron-withdrawing function will increase the coupling kinetics, resulting in decreased salt stability [3,13,27]. The dyes series 161 were obtained from previously obtained diazonium salt with the following 3-(N,N-diethyl)amino acetaniline coupling component.…”

“…To overcome these drawbacks, replacing water by supercritical carbon dioxide as the dyeing media brings serious benefits. Supercritical carbon dioxide dyeing offers numerous advantages such as highly limited environmental impact, mitigated polymer swelling, low surface viscosity favoring dyeing agent penetration, and diffusion with limited by-product formation [5][6][7][8][9][10][11][12][13]. Furthermore, it has been demonstrated that dyeing under supercritical carbon dioxide environment suppresses product denaturation and promotes dye-stuff recovery.…”

“…As shown by Hou et al, supercritical carbon dioxide forms under a pressure of 7.38 MPa and a temperature of 31.1 • C, which favor a stable dyeing environment for the formation of a uniform dye phase and avoiding phase segregation between dye and host during dyeing [1]. Supercritical carbon dioxide has shown excellent performances for the dyeing of bio and synthetic polymer including wool [14], polyester [15], polystyrene [16], polyurethane [17,18], nylon [19,20], polyethylene terephthalate (PET) [13,15,21,22], and cotton [2,6]. During supercritical carbon dioxide dyeing (SDD), the free volume of fiber molecular chain expands, resulting in higher disperse dye penetration and diffusion without using secondary agents [21].…”

“…Coupling and diazonium salt precursor side chain chemical group are known to modify the resulting electron pushing-pulling equilibrium at the chromophore vicinity [3,30,31]. For instance, our group recently demonstrated that the position of electron withdrawing methoxy group on the diazonium salt provide a remarkable pathway to deepen the chromophore light absorption capability [13]; thereby translating a significantly high dye uptake within the dye host with a strong pulling effect from the chromophore [32,33]. A similar effect was observed by Zhang et al; they observed improved dyes fastness using of aromatic hydroxyl group side chain disperse azo dye [3].…”

Novel Yellow Azo Pyridone Derivatives with Different Halide Atoms for Image-Sensor Color Filters

“…Green colorants cannot perfectly absorb blue light, and yellow additives should be added to a green colorant mixture to achieve high color purity of green [ 7 ]. Several dyes have been reported for yellow color, and a popular commercial yellow pigment is Y138 ( Scheme 1 ) [ 12 , 13 , 14 , 15 ]. The synthesized azo pyridone derivatives were studied to optimize their optical, thermal, and solvent stabilities depending on the chemical structures, and their potential as yellow color-filter materials was evaluated.…”