Fluorescence of Polyureas Based on 1,5-Naphthalene Diisocyanate.

Abstract : Polyureas based on 1,5-naphthalene diisocyanate (NDI) form intramolecular excimers in dilute solution. The excimer formation is enhanced in benzene which is a relatively poor solvent for NDI based polyureas. Photolysis in dimethyl formamide solution results in a decrease in the overall intensity and a shift to the red, due most likely to photo-Fries product formation. Excimer fluorescence in the polyurea films is directly dependent on the nature of the diamine reacted with NDI. The excimer fluorescence is particularly strong for the polyurea films based on NDI and 1,12-diaminododecane.