Study on Spectroscopic and Dyeing Characteristics of Curcumin on Poly(lactic acid) and Poly(ethylene terephthalate) Fabrics

Abstract

This research aimed to study the use of curcumin as a natural dye for dyeing poly(lactic acid) and poly(ethylene terephthalate) fabrics. The study found that curcumin was dyeable on PLA and PET, providing a brilliant yellow color on the fabric. Curcumin could build up very well on PLA, while lower build up was on PET. At the same applied concentration, higher color yield was observed on the dyed PLA fabric. To achieve the same visual color yield, a significantly lower concentration of curcumin was required for PLA as compared with PET. The color shade of curcumin-dyed PLA differed from the PET analogue. A bathochromic shift of the K/S curve was found when the substrate was changed from PLA to PET. The influence of polymer media on the spectroscopic properties of curcumin could be elucidated by measuring absorbance properties of curcumin in ethyl acetate and methyl benzoate, being representatives of PLA and PET, respectively. At the same concentration, curcumin solution in ethyl acetate exhibited higher absorbance than that in methyl benzoate, corresponding to the deeper shade obtained when dyed on PLA as compared with PET. Bathochromic shift of absorbance curve was also observed when the solvent was changed from ethyl acetate to methyl benzoate.