Coloration of Ultra High Molecular Weight Polyethylene Fibers Using Alkyl-substituted Monoazo Yellow and Red Dyes

UHMWPE fibers were dyed with yellow and red dyes having different length of alkyl substituents on monoazo chromophores. The dyeability was investigated at various conditions and fastness of the dyeings was examined. As the length of alkyl substituents increased, the dyeability toward UHMWPE fibers tends to be improved gradually up to propyl or butyl groups and then decreased for the longer alkyl substituents. Color strength of the fabrics was increased with the increase of dyeing temperature from 100 to 130 degrees C. From the dyeing rate, equilibrium dyeing at 130 degrees C was achieved at 2 similar to 3 h. The color fastnesses to washing, rubbing, and light of the dyeings were good showing higher than 4 ratings except for light fastness of the red dye.