On the Photophysical and Photochemical Characteristics of Triazene-Cinnamic Acid Polymeric Fluorescent Brighteners

Replacing one of amino compounds of traditional fluorescent brighteners with Cinnamic acid,series of the triazene-cinnamic acid polymeric fluorescent brighteners were synthesized through three-step condensation reaction and polymerization reaction with styrene.The photophysical and photochemical characteristics and whitening properties in aqueous solutions and N,N'-dimethyl formamide were studied by ultraviolet absorption spectra,fluorescence emission spectra,photoinduced isomerization phenomena and paper application test of PFBs.The effect of concentration and polarity of solvents on fluorescence properties were studied.The results show that the light stability and fluorescence quantum yield of PFBs were greater,and photoinduced isomerization was lower.At the same time a red shift of fluorescence emmission wavelength and fluorescence quantum yield increaseing with the increase of solvent po(?)arity.When the concenteation was over 1 g/mL,the fluorescence was quenched.Meanwhile, the type of substituents in the triazine ring can affect directly the concentration of trans- and cis-isomers, but not affect significantly absorption- fluorescence assignments.