The design of novel strong navy reactive dyes

In the current work novel navy and black fibre-reactive dye molecules were designed, synthesised and evaluated technically against the market leading dye, C.1. Reactive Black 5. Novel intermediates were synthesised using a Michael-type addition of 4aminophenyl- p-vinylsulphone onto various primary and secondary amines. The resulting novel bis(aminoaryl) intermediates were isolated and characterised, before being tetrazotised and utilised as linker molecules in the synthesis of four novel reactive dyes, each possessing two 'twice coupled H-acid' units. These reactive dyes were then applied to cotton in an exhaust dyeing process, at different concentrations, and their dyeing performance was compared to that of the market leading dye. The novel dyes were up to 20% stronger on the cloth than the reference dye. This first series of dyes derived from novel linker intermediates had molar extinction coefficients of around 90,000 L mor1 cm-1 . The second series of dyes was derived from commercially available linker intermediates, which allowed a different degree of electron transfer from one chromophoric part of the molecule to the other. As a result of electron transfer, the molar extinction coefficients increased up to 144,000 L mor1 cm-1 . It was found that the structure of the linking molecule has a significant influence on the 3-dimensional structure of the overall dye molecule and thus on its dyeing performance, for example the dye derived from 3,3'-diaminodiphenyl sulphone performed much better, than its para-isomer. Arising from the unexpectedly large difference in technical properties of isomeric dyes, a series of eight isomeric dyes was synthesised and evaluated. The differences in dyeing performance were clearly related to their 3dimensional structures. It was found that dyes possessing a meta-sulphone linker were technically superior to the para-isomers. The isomers with meta structures appeared more hypsochromic with a wider half band width, while the para linker had a bathochromic influence and having a shorter half band width. All dyes performed better, at high concentrations, when applied at higher temperature, i.e. 80°C compared to 60 °C, possibly attributable to their size. A fourth series of four novel bis(monochlorotriazinyl) dyes was prepared from an identical dyebase, but with varying degree of sulphonation. This resulted in different levels of anionic charge, which influenced the dyes' solubility and dyeing performance. A number of eight sulphonate groups was found to be the optimum in terms of solubility and dyeing performance, but that the optimum number of sulphonate groups is strongly dependent on the type of chromophore.EThOS - Electronic Theses Online ServiceGBUnited Kingdo