Dyeing and Spectroscopic Properties of Natural Dyes on Poly (Lactic Acid) and Poly (Ethylene Terephthalate) Fabrics

The current research studied the dyeing properties and spectroscopic characteristics of natural dyes on PLA and PET fabrics. The natural dyes used were the dyes extracted from turmeric and cassumunar powder and thecommercial dyes viz. Natural Orange and Natural Red Brown.The water solubility and partition of the dyes in octanol andwater (logP) were studied. It was found that the dyes with poorwater solubility that were the turmeric and cassumunar dyesexhibited a high degree of exhaustion and visual color yield (K/S)than the readily water soluble commercial dyes viz. NaturalOrange and Natural Red Brown. Turmeric and cassumunardyes can be used for dyeing PLA and PET fabrics to amedium-deep shade with the turmeric dye providing a deepershade. The fluorescence properties of the turmeric andcassumunar dyes were examined on the PLA and PET fabricsand it was observed that the dyes exhibited a strongerfluorescence emission on PLA than PET for both turmeric andcassumunar dyes. Cassumunar dye displayed less fluorescenceproperties than turmeric dyes on both fabrics. The fluorescenceemission properties of the turmeric dyes at different K/S levelswere also investigated.