Synthesis of fluorescent dyes for polyolefin fibers and their fluorescence emission properties

Two novel greenish-yellow fluorescent dyes sharing the same chromophore were synthesized. Dibutyl groups were introduced into the chromophore to enhance their affinity for extremely hydrophobic polyolefin materials, such as polypropylene and ultra-high molecular weight polyethylene (UHMWPE). Despite the similarity in their chromophores, the dye-containing sulfur atoms exhibited significantly superior fluorescence emission properties compared to the dye-containing oxygen atoms, likely due to the heavy atom effect. Comparative experiments involving different dyes, fabrics, and dyeing conditions demonstrated that polyolefin fabrics, previously undyeable with commercial dyes, were successfully dyed with the synthesized fluorescent dyes, maintaining excellent fluorescence properties after application. Additionally, the dyed fabrics exhibited excellent washability and color fastness, except for light fastness.