Synthesis and Characterization of New Fluorescent Polymerizable Dyes Based on Naphthalimide

Two new polymerizable fluorescent dyes based on naphthalimide derivatives wereprepared. For this purpose, acenaphthene as a primary material was brominatedand further reacted by various unit processes such as oxidation, imidation andamination in order to obtain polymerizable fluorescent dyes. The UV-vis spectrophotometryof the synthesized dyes in chloroform represents dyes that havewavelength of maximum absorption between 441-443 nm with extinction coefficientsfrom 56.83 to 60.46 l.g^-1.cm^-1. The synthesized dyes have been characterized usingdifferential scanning calorimetry (DSC), FTIR, 1H NMR, UV-vis spectroscopy andfluorometry. These dyes were copolymerized with methyl methacrylate and twointrinsically coloured copolymers were obtained. It is assumed that 97-99% of the dyesare chemically bonded to polymer chains. The fluorescent characteristics of copolymersin the solid state were determined by fluorometer and it was found that they haverelatively high quantum yields (70-89%). Two synthesized copolymers containingpropyl and butyl have also stock s shifts (λF -λA) about 75 nm and 61 nm, respectively.Thermal properties of the copolymers were evaluated by dynamic mechanicalthermal analysis. The results showed that the glass transition temperatures of thesynthesized copolymers containing propyl and butyl groups are similar to each other. Itmeans that the nature of alkyl group (propyl or butyl) does not play significant role inthe context of Tg change.