Synthesis and Characterization of New Photo-responsive, Ortho and Para Oriented Azomethine Polymers

Abstract

Five new azomethine polymers having aliphatic-aromatic moieties were synthesized by polycondensation reaction of dialdehydes and diamines. The dialdehyde monomers differ only in the orientation of the aromatic ring (ortho or para) and were synthesized by condensation reaction between aromatic aldehyde and 1,6-dibromohexane. The molecular mass of the monomers was recorded through E.I mass spectrum. The polymers structures were confirmed by elemental microanalysis, FT-IR, ¹HNMR and UV-Vis Spectroscopy. The morphology of monomers and polymers was evaluated by scanning electron microscopy (SEM). All the polymers were soluble in DMSO (on heating) and somewhat in other solvents. Thermal stability of polymers was analyzed by thermogravimetry (TG) and differential thermal analysis (DTA), all the polymers showed good thermal stability higher than their corresponding monomers. The TG of polymers indicated maximum rate of weight loss (T_max) within 412-708 °C. Fluorescence emission spectra of polymers were recorded and the results indicated that all the polymers were photo-responsive and indicated 1 to 4 emission bands with maximum within 349-606 nm. The limit of detection of polymers was within 0.625-1.25 µg/ml. The polymers were also examined for their antimicrobial activities against bacteria and fungi.