双三嗪-肉桂酸聚合型荧光增白剂的光物理化学性质研究

以肉桂酸盐替代其中一种氨基化合物,经过三步缩合反应和苯乙烯的共聚反应,合成了系列双三嗪-肉桂酸聚合型荧光增白剂（PFBs）。用紫外光谱、荧光光谱、光致异构化及应用试验等手段研究它们在水和N,N’-二甲基甲酰胺（DMF）溶液中光物理化学性质及增白性能,同时考察浓度和溶剂极性及化合物结构对荧光性能影响。结果表明此双三嗪-肉桂酸聚合型荧光增白剂,可明显提高光的稳定性及荧光量子产率,降低光致异构现象;同时随着溶剂极性增大,荧光量子产率增大,荧光波长红移;当浓度超过1×10^-4g/mL时出现荧光浓度自猝灭。同时三嗪环上取代基类型直接影响顺反式异构体的比例,但对光吸收和荧光分配并无显著影响。

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 ernmission wavelength and fluorescence quantum yield increaseing with the increase of solvent poiarity. 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.