The synthesis of novel photostable fluorescein-based dyes containing an s-triazine UV absorber and a HALS unit and their acrylonitrile copolymers

Two novel fluorescein-based dyes, containing both a hindered amine radical scavenger and an s-triazine UV absorber as well as a polymerizable allyl function, were designed as multifunctional photostable fluorophores capable of simultaneously fluorescently colouring and photostabilising polymers; their absorbance and fluorescence properties in solution were determined. The compounds were copolymerized with acrylonitrile to yield polyacrylonitriles of intense colour and fluorescence. The influence of the novel compounds on the photostability of the coloured copolymers was compared to that offered by conventional fluorescent dyes that did not contain either a UV absorber or a hindered amine radical scavenger component. Significant photostabilisation was observed, which can be attributed to the synergistic effects of the two stabilizer units.