Curcumin is a natural dye used in a wide variety of applications including textiles. In this study, it was attempted to determine whether curcumin can be modified for mordant-free coloring of textiles. Curcumin was chemically modified in aqueous system using glycidyltrimethylammonium chloride. The modified product called CurGTMAC was analyzed for structure by mass spectroscopy and examined for absorption properties. Results showed that its absorbance significantly shifted to UV region with an extinction coefficient high enough to function as a natural-based dye with UV protective properties. After applying CurGTMAC to cotton fabrics pre-treated with citric acid and sodium hypophosphite, excellent UV protection property and good durability t...