Preparation and optical properties of coumarin fluorescent polymer

Employing toluene-p-sulfonic acid as the activator, 7-hydroxy-4-methyl coumarin was synthesized by dehydration condensation reaction of resorcinol and ethyl acetoacetate through the Pechmann method. Cyanuric chloride was used as the crosslinking monomer, a water-soluble fluorescent polymer was prepared through joining the 7-hydroxy-4-methyl coumarin, ultraviolet absorber 2, 4-dihydroxy-benzophenone and a certain percentage of acrylamide. The molecular structures were characterized by IR spectra and 1H NMR, and the optical properties were measured by UV spectra and fluorescence spectra. The application effect of the polymer in paper sheet was tested. The results show that the Stokes shift of polymer (3121.2 cm-1) is less than monomer (5221.5 cm-1), the polymer steric resistance change is smaller, and the energy loss is less. These indicate that the polymer owns a more stable structure, a better light stability, and a better effect in UV ageing resistance on paper sheet than fluorescent monomer.