Spectral, dyeing and antimicrobial properties of some monoazo naphthalimide dyes on polyamide

A series of monoazo disperse dyes based on naphthalimide has been applied on to the nylon fabrics. The build-up values and dyeing properties of these dyes, such as leveling, and wash, light and rub fastnesses on nylon fabrics have been assessed. The dyes N-2-aminomethylpyridine-1,8-naphthalimideazo-4′′-N,N-diethyl meta toluidine (A) and N-2-aminomethylpyridine-1,8-naphthalimide-azo-2′′acetylamino-4′′N,Ndiethyl aniline (B) show higher build-up values on polyamide fabrics as compared to the dyes N-2-aminomethylpyridine-1,8-naphthalimideazo4′′N-hydroxy ethyl-Nethyl aniline (C) and N-2-aminomethylpyridine-1,8-naphthalimideazo4′′N-hydroxy ethyl-Nethyl aniline quaternized with 1bromobutane (D). All of the applied dyes exhibit excellent rub fastness, good wash fastness and moderate light fastness on nylon fabrics. In addition, the molar extinction coefficient, wavelengths of the maximum absorption and solvatochromism effects have also been studied using chloroform, toluene, and DMF as solvents. Positive solvatochromism occurs when toluene is replaced by DMF as solvent. The antimicrobial properties of dyed fabrics are evaluated against various bacteria; the dyed fabrics exhibit antimicrobial efficacy against both Gram-positive and Gram-negative bacteria.