Mediterranean Journal of Basic and Applied Sciences (MJBAS) Volume 8, Issue 3, Pages 130-142, July-September 2024 ISSN: 2581-5059 130 Synthesis of a series of Homo-Bifunctional Azo Reactive dyes and Evaluation of their dyeing properties on Silk fabric Olua, E.B. 1* , Oforghor, A.O. 2 , Musharraf, A.B. 3 & S.M. Jagaba 4 1 Department of Home Science and Management, University of Nigeria, Nsukka, Nigeria. 2 Department of Home Science and Management, Nasarawa State University, Keffi, Nigeria. 3 Department of Chemistry, Federal University Dutsinma, Nigeria. 4 Chemistry Department, School of Secondary Education (Sciences), Federal College of Education, Katsina, Katsina State, Nigeria. Email: ekwutosi.oluah@unn.edu.ng * DOI: https://doi.org/10.46382/MJBAS.2024.8314 Copyright © 2024 Olua, E.B. et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Article Received: 17 June 2024 Article Accepted: 26 August 2024 Article Published: 29 August 2024 ░ 1.0. Introduction Oforghor, et al. (2023C) and Zhangr, et al. (2019) reported that reactive dyes were initially introduced commercially for application to cellulosic fibres, and this is still their most important use. The growth rate of reactive dyes for cellulosic fibres is expected to continue increasing. Souhangir, et al. (2022), Shankarling, et al. (2017), Mortazavi-Derazkola (2017) reported that this is expected because reactive dyes continue to gain market share at the expense of other dye types such as azoic dyes. Mohamed, et al. (2018), Lokhandyala and Kapadiya (2017) stated that reactive dyes have also been developed for application on protein-silk and wool fibres and polyamide - silk fibres respectively. Several heterocyclic compounds are extensively used in dye chemistry for textile or non-textile applications in recent years (Lewis, 2014). These dyes are now marketed to produce a full range of dispersed dyestuffs without the use of colorants based on heteroaromatic diazo components (Mokatari, et al. (2005). Oforghor, et al. (2023C), Shindy (2017), and Shor (2002)) reported that most of the heterocyclic dyes are derived from the diazo components consisting of five-membered rings containing one or more nitrogen heteroatoms, with the rings being fused into another aromatic ring. Lewis (2009), Lewis and Siddique (2008) and Taylor (2000) reported that the dyes with heterocyclic diazo components have been intensively investigated, to produce bright and strong colour shades ranging from red to greenish blue on synthetic fabrics. These results led to commercial products to replace the conventional azobenzene disperse dyes. The nitrosubstituted aminothiophenes, and aminothiazoles are primarily of importance as diazo components (Patel et al., 2013). Recently, Towns has summarized the developments in azo disperse dyes derived from heterocyclic diazo components (Patel et al., 2002). Non-textile uses of heteraylazo disperse dyes have been explored, for example in reprographic technology, functional dye applications, and non-linear optical systems (Patel and Patel, 2012). The monoazo dyes containing heterocyclic rings or carbocyclic rings result in brighter and often deeper shades than their disazo or trisazo analogues. On the other hand, the disazo or trisazo dyes are very important in applications such as disperse dyes for ABSTRACT This paper was conceived with the objective of synthesizing and evaluating some novel bifunctional Dichlorotriazine (DCT) azo reactive dyes. They were synthesized via tetrazotization of 1, 4- benzenediamine followed by the coupling with cyanurated 4-nitroanilino acids components (H-acid, J-acid, Laurent acid, Tobias acid and Gamma acid) respectively. The spectra properties (UV-vis spectra, FT-IR, 1H NMR and MS) of the synthesised dyes are reported. The novel bifunctional dichlorotriazine (DCT) azo reactive dyes were applied on silk fabric using the exhaustion techniques. The total exhaustion and fixation values were estimated. The basic fastness properties to washing, light and perspiration of the dyes on silk fabric were discussed in terms of their chemical structure. The dyes showed good build up, levelling and fastness properties on silk fabrics. Keywords: 1, 4-benzenediamine; Azo dyes; Fastness properties; Reactive dyes; Silk fabric.