NOPR Collection:

Syntheses of azo disperse dyes from 2-amino-6-briomobenzothiazole and their application on polyester fibres

Tue, 01 Mar 1994 00:00:00 GMT

Title: Syntheses of azo disperse dyes from 2-amino-6-briomobenzothiazole and their application on polyester fibres Authors: Modi, B R; Desai, K R Abstract: Eleven azo disperse dyes, viz. (i-bromo-2-[H/substituted- 4'-(N, N-disubstituted amino)phenylazo]benzothiazoles (Va-k), were prepared by coupling diazotized 2-amino-6-bromobenzothiazole (II) with various substituted aniline derivatives (lVa-k) and their dyeing performance on polyester fibres was assessed. All the compounds, when applied on polyester fibres as 2% shade, gave moderate to good light fastness, good to excellent fastness to washing, perspiration, rubbing and sublimation, and very good to excellent exhaustion. Page(s): 46-49

Syntheses of 8-N-(aryl/hetaryl)-8H-acenaphtho[4, 5-d][1, 2, 3]triazoles and their application on polyester fibres as fluorescent brighteners

Tue, 01 Mar 1994 00:00:00 GMT

Title: Syntheses of 8-N-(aryl/hetaryl)-8H-acenaphtho[4, 5-d][1, 2, 3]triazoles and their application on polyester fibres as fluorescent brighteners Authors: Rangnekar, D W; Lokhande, S B Abstract: Acenaphthene (I) was nitrated and reduced to 5-aminoacenaphthene (II), which was then coupled with a variety of aryl/hetaryl diazonium salts (IIIa-i) to give 4-(aryl/hetaryl)azo-5-aminoacenaphthenes (IVa-i). These ortho-aminoazo compounds (IVa-i) were then oxidized in refluxing DMF to obtain corresponding 8-N-(aryl(hetaryl)-8H-acenaphtho[4, 5-d][1, 2, 3)triazoles (Va-i). The compounds containing nitro groups (Vd-g) were converted to their acetamido derivatives (VId-g). The compounds Va-c, VId-g, Vh and Vi were applied on polyester fibres as fluorescent brightener and It was observed that the compounds Vc and Vi showed excellent whitening effect whereas the compounds Va, Vld and Vh showed good whitening effect. Page(s): 42-45

Dyeing of jute: Effect of progressive removal of hemicellulose and lignin

Tue, 01 Mar 1994 00:00:00 GMT

Title: Dyeing of jute: Effect of progressive removal of hemicellulose and lignin Authors: Ganguly, P K; Chanda, Subhas Abstract: Progressive removal of hemicellulose and lignin from jute separately affects the functional group (- CHO and - COOH) pattern and consequently the dyeability of the fibre with respect to an acid and a direct dye. Uptake of direct dye by jute fibre improves on hemicellulose removal while that of acid dye suffers adversely at low levels of hemicellulose removal but improves when about 70% of hemicellulose is removed. Removal of lignin from jute increases its - CHO and - COOH contents and lowers the uptake of both acid and direct dyes by the fibre. Page(s): 38-41

Single bath bleaching-dyeing of jute fabric with hydrogen peroxide-direct dye combinations

Tue, 01 Mar 1994 00:00:00 GMT

Title: Single bath bleaching-dyeing of jute fabric with hydrogen peroxide-direct dye combinations Authors: Pandey, S N; Chattopadhyay, S N; Pan, N C; Day, A Abstract: Hydrogen peroxide bleaching and direct dyeing of jute fabric has been carried out by three different process sequences, namely conventional two-step bleaching-dyeing, single bath bleaching-dyeing and single bath bleaching-dyeing with intermediate addition of reducing agent, and the colour strength of dyed samples evaluated using a computer colour matching system. It is observed that the colour yield in case of single bath bleaching-dyeing with intermediate addition of 2 g/l reducing agent is well comparable with that obtained in conventional two-step bleaching-dyeing. Further, the colour yield in single bath process depends on the nature of dye and its compatibility with alkaline oxidizing condition. The fabric dyed by single bath technique shows better wash fastness compared to that dyed by two-step conventional process. The method of dyeing has no effect on λ_max value. This confirms no alteration in the hue and tone of any sample dyed with any particular dye by single bath bleaching-dyeing process. Page(s): 34-37