Synthesis and application of alkyl-substituted disazo yellow dyes for unmodified polypropylene fiber

Abstract

The several disazo dyes having different alkyl substituents were synthesized to dye unmodified polypropylene fiber. The affinity of the dyes onto unmodified polypropylene was increased with the increase of the length of alkyl substituents. Therefore, the heptyl-substituted dye having the longest alkyl group in this experiment showed very high color strength of dyeings with K/S value of over 24 at maximum absorption wavelength. The color fastnesses to washing, rubbing and light were also improved significantly for the longer alkyl substituted dyes, so that the heptyl-substituted dye exhibited a rating of 4~5 for all kinds of fastnesses.

Synthesis of Red Disperse Dyes with Various Diazo Components and Coloration of Unmodified Pure Polypropylene Fibers

“…In this procedure, the uniform mixture of dyes and dispersant (DDDMAB) was prepared. The 1 hour exposure in an ultrasonic apparatus after the addition of water to this mixture makes uniform and stable dye solution by the dispersion activity of DDDMAB [9][10][11][12][13][14][15] . This solution was finally used for dyeing.…”

“…The previous studies show that the dyeing of polypropylene fibers without any physical and chemical modifications is possible at the established process by super hydrophobic dyes having long alkyl substituents which impart extreme hydrophobicity to the dyes [9][10][11][12] . Anthraquinoid blue dyes were selected and investigated at first 9,10) .…”

“…Anthraquinoid blue dyes were selected and investigated at first 9,10) . And then disazo and monoaz yellow dyes were synthesized and examined 11,12) . Apart from that, in order for new series of dyes to be utilized for textiles, it is necessary to acquire at least three dyes of primary colors, such as blue, yellow, and red.…”

Calculation and Analysis of Hydrophobicity of the Dyes Synthesized for Unmodified Polypropylene Fibers Using Molecular Descriptors

“…4 according to the length of alkyl substituents [4][5][6][7] . As the length of alkyl substituents increased, the dyeability toward polypropylene fiber tends to be improved dramatically for all the dyes.…”

“…To have strong affinity to the hydrophobic fibers like polypropylene, dyes also need to have comparable hydrophobicity. Previous studies showed that the dyeing of polypropylene fibers without any physical and chemical modifications was possible at the established process by super hydrophobic dyes having long alkyl substituents which imparted significant hydrophobicity to the dyes [4][5][6][7] . As a successive study, logP values were calculated in order to express the hydrophobicity of the dyes numerically by a semi-empirical method using Chem3D software.…”