62 ISSN 1229-9197 (print version) ISSN 1875-0052 (electronic version) Fibers and Polymers 2015, Vol.16, No.1, 62-66 Ultrasound Effect on Dyeing Wool Fibers with Two Anthraquinone Dyes Andreia Sanislav, Magdalena Fogorasi 1 * , Michaela Dina Stanescu * , Simona Muntean 2 , and Mihaela Dochia 1 Department of Organic Chemistry, Politehnica University, Bucharest 011062, Romania 1 Department of Automation, Industrial Engineering, Textiles and Transport, Aurel Vlaicu University, Arad 310330, Romania 2 Institute of Chemistry of Romanian Academy, Timisoara 300223, Romania (Received July 18, 2013; Revised May 4, 2014; Accepted September 20, 2014) Abstract: Environmental and quality demands generate new approaches for finding better solutions in textile dyeing. A less polluting and more ecological procedure has been investigated, on this purpose. This study reveals the influence of ultrasounds (US) on wool dyeing. It presents comparatively the dyeing results for two frequently used anthraquinone dyes, one reactive (CI Reactive Blue 19) and the other acid (CI Acid Blue 62), applied on wool fibers. The comparison between the classic and the US dyeing procedures was performed in terms of: dye bath exhaustion, wash fastness and the color analysis. The dye aggregation was evidenced through the visible spectra, and the effect of US in this respect, was underlined, especially for the acid dye case. For the reactive dye, the higher bath exhaustion in US dyeing conditions was explained. Keywords: Reactive Blue 19, Acid Blue 62, Wool fibers, Dye aggregation, Ultrasound dyeing Introduction Pollution prevention is one of the main focuses in textile research. Dyes are severe pollutants due to their color as well as their resistance to biodegradation, and methods for their removal are continuously developed [1-3]. At the same time, though textile dyeing is a very ancient occupation [4], for obtaining good quality products, with high reproducibility, work is still to be done. The dyes associate in solutions forming dimmers, trimmers, etc. [5] making difficult the leveling of a textile fabric coloration. One way to spot such dye associations is by performing their visible spectra. The aspect of absorption curves at different dye concentrations may illustrate the formation of such aggregation in solution [5,6]. The dyeing procedure of wool fibers with two anthraquinone dyes has been studied trying to find a way for higher dye bath exhaustion and better quality for the dyed stuff. The dyes are: Reactive Blue 19 (RB 19) dye (1) and Acid Blue 62 (AB 62) dye (2), belonging to two important tinctorial classes: acid and reactive dyes, often used for wool dyeing. Their chemical structures are presented in Figure 1. The capacity to aggregate of these dyes has been investigated. A possibility, to remove the inconvenience of an unleveled dyeing due to such aggregation, would be the application of a high performance stirring. A way for managing it is by using ultrasound (US) devices [7-9] during the dyeing process. There are a number of papers about US influence on textile dyeing process, some of them being mentioned here. In these papers, the influence of US dyeing has been evidenced for dyes from natural sources [10-14], but also for synthetic dyes [15-17]. A comprehensive analysis of these applications was performed by Vajnhandl and Majcen Le Marechal [18]. For a broad picture, studies concerning the influence of dye chemical structure, as well as its tinctorial affinity, during US assisted dyeing process, are still of interest. Thus, the dyeing of wool, a natural proteinaceous fiber, compatible with the dyes 1 and 2, has been performed, in the presence or not of US, and the results comparatively discussed. Experimental Chemicals Reactive Blue 19 (RB 19) dye [2-(3-(4-amino-9,10-dihydro- 3-sulfo-9,10-dioxoanthracen-4-yl)aminobenzenesulfonyl)ethyl disodium sulfate; CAS 2580-17-1] (1), Acid Blue 62 (AB 62) dye (1-amino-4-cyclohexylamino-9,10-dihydro-9,10- dioxoanthracene-2-sulfonic acid, sodium salt; CAS 4368- 56-3) (2), the leveling agent Keriolan A2N, and the washing agent Felosan RGN were kindly supplied by BEZEMA AG. All the other chemicals were purchased from Sigma, Steinheim, Germany and were of analytical grade. Textile Materials Merino wool top, with fiber diameter of 21 μm was used. The wool was previously degreased with Na 2 CO 3 (solution of 5 g/l) and Felosan RGN as surfactant (5 ml/l) and, *Corresponding author: mfogorasi@yahoo.com *Corresponding author: smichaeladina@yahoo.com Figure 1. Chemical structure of the anthraquinone dyes. DOI 10.1007/s12221-015-0062-5