Disperse dyes: 4‐hetarylazo derivatives from N‐β‐cyanoethyl‐N‐β‐hydroxyethylaniline

Abstract

Aminothiazoles, benzothiazoles, thiadiazoles and thiophenes were diazotised and coupled to N‐β‐cyanoethyl‐N‐β‐hydroxyethylaniline to give dyes which coloured polyester in orange to blue hues. The colour of the dyes is discussed with respect to the nature of the heterocyclic ring and substituents therein. Solvent effects on the visible absorption maxima of some of the dyes are also reported.

Visible absorption spectra of some novel heteroarylazo disperse dyes derived from 2‐hydroxy‐1,4‐naphthoquinone

“…Heterocyclic azo disperse dyes tend to be more strongly affected by solvents than those based on azobenzene; this is a consequence of the increased polarity of the system, especially in the excited state. Similar effects for dyes containing benzothiazolyl, thiazolyl and thienyl moieties have also been reported for derivatives of N-β-cyanoethyl-N-β-hydroxyethyl aniline [14][15][16][17][18].…”

Colour and Dyeing Properties of Hetarylazo Disperse Dyes: Visual and Instrumental Evaluation

“…are given. As it was expected [3,4,7,10,11] dyes 1(a-d)-3(a-e) derived from the heterocyclic diazo compounds benzothiazole and benzoisothiazole derivatives, i.e heterocyclic systems containing sulphur as the π-excessive heteroatom representing a very electronegative diazo component, have a marked bathochromic effect compared with the corresponding benzenoid compounds probably due to the greater stabilization of the excited state.…”

Dyeing of poly(lactic acid) fibres with synthesised novel heterocyclic disazo disperse dyes

“…However, PLA fibres have a higher sensitivity to alkali pH values than PET, and therefore milder alkali soda ash was utilised instead of sodium hydroxide for PLA. It is known that the reduction clearing temperature should be less than the glass transition temperature ( T g ) of the respective fibre so as not to remove any fixed disperse dye from the fibre 35 . All of the clearing temperatures were selected according to the T g of respective fibres.…”

“…It is known that the reduction clearing temperature should be less than the glass transition temperature (T g ) of the respective fibre so as not to remove any fixed disperse dye from the fibre. 35 All of the clearing temperatures were selected according to the T g of respective fibres. Therefore, the clearing temperature of PLA was below that of PET fibre.…”