Synthetic Fiber Dyeing with New Pyrazole Disperse Dyes and Their Colorimetric and Fastness Properties

A series of disazo pyrazole disperse dyes were synthesized and reported at our previous work. These 8 synthesized disazo pyrazole disperse dyes (3a-3h) were applied to poly(lactic acid) (PLA), poly(ethylene terephthalate) (PET), and polyamide 6.6 fibers. Their colorimetric and color fastness properties were investigated. All studied fibers dyed with these synthesized dyes exhibited yellow-red shades. 3c (p-Cl), 3e (m-Cl), and 3h (o-Cl) disazo disperse dyes, having auxochrome -Cl, led to the lowest color yield values for all three studied fibers. The same dyes resulted in higher color strength with darker shades on the PET and PLA fabrics in comparison PA 6.6 fabrics. 3a (p-NO2), 3b (p-OCH3), 3d (m-NO2), 3f (o-NO2), and 3g (o-OCH3) disazo disperse dyes can be recommended for PLA and PET dyeing from the color point of view leading to medium to heavy depth of shades. The wash, alkaline and acidic perspiration, dry and wet rub, water and sea water fastness levels of PLA, PET, and PA 6.6 samples dyed with 3a-3h dyes were generally quite high and in the commercially acceptable range with few exceptions. Dyed PLA fabrics displayed better sublimation fastness levels than dyed PET and PA 6.6 fabrics. Synthesized disperse dyes resulted in high light fastness performance on especially PET and PLA fibers. Light fastness level was better for dyed PET samples by comparison with dyed PLA and PA 6.6 fabrics.