Syntheses of Polymeric Azo Dyes of Pyrazolone Series

Synopsis

To investigate polymeric dyes having excellent bleeding resistance and light fastness, polymeric azo dyes of pyrazolone series were prepared from homopolymerization of 4-arylazo-3- methyl-1 –[p- (methacrylamido) phenyl] - 2-pyrazolin- 5-one in which the aromatic moieties are C₆H₅, p-CH₃C₆H₄, m-CH₃C₆H₄, p-CH₃OC₆H₄, m-CH₃OC₆H₄, p-CLC₆H₄, m-CLC₆H₄, p-NO₂C₆H₄, m-NO₂C₆H₄,p-(CH₃)₂NC₆H₄. It was proved from GPC analysis that the polymeric azo dyes are made of molecules of oligomeric range, and it was estimated from IR and NMR spectra that the polymeric as well as monomeric azo dyes are present as a hydrazone form. The comparison of light fastness of the polymeric and monomeric azo dyes was carried out in MMA resin cast film. Appreciable difference in light fastness between the polymeric and corresponding monomeric azo dye was not observed.