PREPARATION OF DYED AZOLIGNINS ON LINEN COTTONIN MODIFIED BY ENZYMES

Abstract

The possibility of using azoreaction for obtaining colored like-cotton flax (cottonin) are evaluated in this article. For the process of disfiling (disfibering, disenchantment) enzymes Pulpzyme HC and Scourzyme L ("Novozymes A/S" (Denmark)) were applied. Diazol scarlet K was used as a diazo component. It is established that the enzymatic modification of ligno-carbohydrate complex promotes opening phenolic hydroxyls. As a result, the reactivity of flax fiber with respect to diazol alum K increases. The spectra of dyed extracted polyphenols of flax were obtained and interpreted for region of 400-700 nm. It was shown that in the spectra of extractive aromatic substances of phenolic nature for the native fiber two maxima at 420-440 nm and 500-520 were appeared nm during the azo coupling reaction. The first maximum corresponds to the compounds formed as a result of the reaction of azo combination with aromatic substances having unexpressed color (chromophore). The long-wave maximum is associated with azo lignins, where the associated and non-associated complexes of aromatic polyphenols of lignin act as the diazocomponent. It is assumed that enzymatic hydrolysis of non-cellulose polysaccharides creates stereo accessibility to the reaction groups of lignin, which is part of the structure of the ligno-carbohydrate complex of flax fiber. The dependence of the function K/S – (K/S)0 for colored flax fibers at different modification methods were obtained and interpreted. The effect of lignin unblocking in after enzymatic cottonization is confirmed. There is a significant increase in the K/S function of colored cottonin in comparison with the results for native short flax fiber. The method of spectrophotometry proved that the maximum effect of color dyeing is provided in the case of the enzymatic modification of Pulpzyme NS if excluded of the washing stage.