Synthesis and Characterization of New Photoresponsive, 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, 1 HNMR 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.

New Fluorescent, Thermally Stable and Film Forming Polyimines Containing Naphthyl Rings

“…Three new monomers (two dialdehydes and one diketone) were prepared by following a reported procedure. [33][34][35] (15.38 ml) were also added to the reaction flask. The contents were refluxed for 5 h at 150 °C with continuous stirring, the resulting product was poured into 500 ml cold water and allowed to form precipitates.…”

“…Three new polymers were synthesized by following reported method [33][34][35] with slight modification in the proce-…”

“…In the present work new meta oriented dialdehyde m-HOB was prepared while its ortho and para oriented isomers were reported in our earlier work. 34,35 Three new polyimines (PmHOBND, PoHONPD and PoHOAND) were prepared by the polycondensation of dialdehydes or diketone monomers (m-HOB, o-HON or o-HOA) with di- amines (1,5-naphthalenediamine or 1,4-phenylenediamine). The polymers have ether linkages, azomethine or imine bonds and spacers of n-hexane between the aromatic rings and the polymer derived from diketone monomer (o-HOA) contains methyl group attached with the imine (C=N) group.…”

Synthesis and characterization of new thermally stable, antimicrobial and red-light-emitting poly(azomethine-ester)s

“…These applications are based on the unique properties of polyesters which in turn depend on their structures; therefore, many researchers are attracted to study the effect of structural variation on the properties of polyesters [1]. The polymers containing azomethine (CH=N) units have many attracting properties such as thermal stability [2,3], fluorescence [4][5][6], antimicrobial activities [7,8] and their use as adsorbent for the removal of heavy metal ions from water systems [8,9]. Therefore, a number of polyesters containing azomethine units also called poly(azomethineester)s have been prepared and interest in the synthesis of new poly(azomethineester)s continue because of their useful applications which include electrical conductance [10], liquid crystalline [11], corrosion inhibition [12], heat resistance [13][14][15], opto(electronic) [16], biocidal activity [17], photoluminescence [18] and fiber-forming ability [19].…”