Photolytic Behavior of Some Popular Disperse Dyes on Polyester and Nylon Substrates

Abstract

The photodegradation products that form when disperse red 1, red 17, and blue 3 dyed fabrics and films are exposed to carbon arc and xenon arc light sources have been identified. The effects of black panel and dye carrier on the nature of the degradation products and the fading process itself were also studied. The results of this research indicate that the same photodegradation products occur in comparisons involving carbon arc versus xenon arc exposures, polyester versus nylon substrates, black panel versus no black panel exposures, and exposures of carrier dyed versus no carrier dyed PET. It is clear that photo-reduction pathways account for the products that form when the two azo disperse dyes (red 1 and red 17) photofade, but photooxidation characterizes the fading of the anthraquinone disperse dye blue 3. The photodegradation products were determined with the aid of GC mass spectrometry and by TLC comparisons with authentic samples.Dyed materials often fade readily upon prolonged exposure to direct sunlight; this problem is particularly troublesome in substrates dyed green or blue. The need for synthetic dyes that possess significantly improved lightfastness has resulted in a great deal of research activity in recent years. This activity has involved, among other things, attempts to define the fundamental processes that occur when dyes are faded, and to determine the effect of chemical constitution on the photostability of dyes.Although the dyestuff literature contains a number of papers decribing possible relationships between the chemical constitution of dyes and their lightfastness [ 1,7,10,11,14,18,20,21,24,26,27,28], few papers have been published suggesting the actual nature of the fundamental photochemical reactions involved when dyed materials are faded by light. Most of the work on the determination of the reaction mechanisms that characterize the photodegradation of dyestuffs has been conducted in solution [2,4,16,19,22]. This work includes a relatively recent paper by Kuramoto and Kitao [ 19], in which they describe the contribution of singlet oxygen to the photofading of arylazonaphthol, indigoid, quinophthalone, aminoanthraquinone, triphenylmethane, and stilbene dyes in the organic solvents methanol, acetone, benzene, and dichloromethane. More recently, Acoria et al. reported [4] that the photolysis of certain monoazo disperse dyes in amide solvents follows zero-order kinetics when done under nitrogen. They concluded that a reducing species was formed photochemically from the solvent which then interacted with the dye, and that the photofading rate increased with increasing solvation of the dye.A few papers have been published [3,5,15,17,23,25] describing work resulting from the fading of dyed films or fabrics. These papers include the recent work of Acoria [5], which suggested that a reductive pathway was involved when nine azo dyes were irradiated on nylon films at 254 nm in the presence or absence of air.Although researchers know that the reaction sequences characterizing the photodegradat...

Characteristics of fading of wool cloth dyed with selected natural dyestuffs on the basis of solar radiant energy

“…Lightfastness has been investigated widely and intensively in developing new dyestuffs [7][8][9][10][11][12]. Most of fading experiments were made under accelerated conditions with artificial light sources such as carbon arc lamp, xenon arc lamp and so on instead of solar radiation.…”

Effect of Substrates on Action Spectra of Fading of a Selected Disperse Dyestuff under Light Radiation

“…It is clearly concluded in this study that the substrate effect of nylon caused a great decrease in the fastness of the dyed specimen in the wavelength range examined. Previously, it was empirically well recognized that nylon decreased the light-fastness of disperse dyes [11,15]. However, the factors that control it were not known; the present research has provided some clues to help in understanding these factors.…”

“…In textile technology, the fading of dyestuffs by light radiation is one of the most important factors influencing the useful wear life of clothing [1][2][3][4][5]. Light-fastness has been investigated widely to obtain knowledge to assist in developing better dyestuffs [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Most fading experiments have been made under accelerated conditions with multichromatic light sources.…”

Photolytic Properties of Ortho-Substituted 4-[N,N-Bis(β- Hydroxyethyl)amino]azobenzenes in Polymer Substrates

“…We have previously observed the photolytic cleavage of N hydroxyethyl groups in azo and anthraquinone dyes in these laboratories [8]. In addition, we and others have reported the reductive cleavage of an azo linkage as the pathway by which closely related dyes undergo photodegradation [1,8], but it does not appear that biphenyl (9) or its derivatives have been reported previously as products of these photolytic reactions. Compounds 4-9 were also present in extracts of xenon arc exposure of cellulose acetate, cellulose triacetate, and polyester fibers that had been dyed with the dyes in this study.…”