SYNTHESIS OF DIAZO DYE USING 4-AMINOPHENOL AND N, N- DIMETHYLANILINE AS COUPLERS AND ITS DYEABILITY POTENTIAL ON MODIFIED LINEN FIBRE

Abstract

The synthesis, properties of diazo dyes derived from 2,4-dichloroaniline using 4-aminophenol and N,N-Dimethylaniline as couplers in a 2 stage reaction was described. The dye was prepared via diazotization and coupling reaction and its colour impact on modified linen fibre was accessed. The intermediate product 4-amino-2-[(E)-(2,4-dichlorophenyl)diazenyl] phenol gave a yield of 97%, M.P. of 147-150 0C, Rfvalue 0.63 (ether/acetone 5:1), λmax of 427 nm and the diazo dye 2-[(E)-(2,4-dichlorophenyl) diazenyl]4-{(E)-[4-(dimethylamino)phenyl] diazenyl} phenol yielded 93%, M.P. 126-128 0C, Rfvalue 0.61 (ether/acetone 5:1), λmax 438 nm. The wavelength, functional groups, number of protons and carbon present in the dye structure were confirmed using UV-Visible, FTIR, 1H-NMR and 13C-NMR respectively. The synthesized dyes afford better light, wash and rub fastness on the modified linen fibre than the untreated linen fibre. This research also used Anova to access the fastness, dyeability and uniaxial tensile strength of chemical modification linen fibre after the acetylaion, benzolation, and methylation treatment. The methylated fibres gave the highest mean value for light, wash and rub fastness, followed by the benzoylated and acetylated fibre, although there is no significant level of difference between them. The maximum range value was 0.67, 1.00, and 0.67 for light, wash and rub fastness respectively. The tensile strength was observed to be high for acetylated fibre with a Young modulus of 271.75 MPa, followed by benzolation fibre with a Young modulus of 140.47 MPa and methylated fibre with a young modulus of 23.78 MPa. Key words: Diazo dyes, fastness properties, modified line fibre, FTIR, 1H-NMR, 13C-NMR