Studies in chemically modified celluloses. V. Affinities of vat dyes for chemically modified celluloses

✍ Scribed by V. A. Shenai; M. Veeramani

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 646 KB
• Volume: 17
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1973.070170607

✦ Synopsis

Abstract

Cotton cellulose was separately oxidized by potassium metaperiodate, potassium dichromate–sulfuric acid, and potassium dichromate–oxalic acid at two oxidation levels, and the resulting oxycelluloses were further modified by treatment with chlorous acid and sodium borohydride in order to prepare a series of chemically modified celluloses with different functional groups. These fiber substances were dyed with leuco‐flavanthrone at 40°C for different periods till equilibrium was reached. Adsorption isotherms were obtained with three purified vat dyes, and thermodynamic affinity of the dyes for the modified celluloses was determined, taking into consideration the adsorption of hydroxyl ions by cellulosic material and of sodium ions by carboxylate groups of oxycellulose. The presence of aldehyde and carboxyl groups is shown to decrease the rate of dyeing as well as the affinity of the dyes.