Syntheses and thermoanalytical studies of some schiff base polymers derived from 5,5′-methylene bis(2-hydroxyacetophenone)

Synthesis and characterization of thermally stable Schiff base polymers and their copper(II), cobalt(II) and nickel(II) complexes

“…doi:10.1016/j.reactfunctpolym.2007.08.012 solubility in most organic solvents due to their rigid chain structure. Some general methods have been used to overcome the limited solubility properties of SBP, for example, insertion of flexible bonds between main chain aromatic rings [1][2][3]. Due to the reagents used for the reaction process, the oxidative polycondensation (OP) may also be regarded as a good example of environmentally benign or green synthetic process of polymeric materials.…”

Synthesis, characterization, and acoustic properties of new soluble polyurethanes based on 2,2′‐[1,4‐phenylenebis(nitrilomethylylidene)diphenol and 2,2′‐[4,4′‐methylene‐di‐2‐methylphenylene‐1,1′‐bis(nitrilomethylylidene)]diphenol

“…Hydrogen bonding in PUs is of great interest because it plays an important role 22 in determining the phase segregation. In all the PUs, sharp bands appearing between 3280 and 3384 cm 21 are due to the presence of hydrogen-bonded NÀ ÀH groups. 23 However, hydrogen-bonded carbonyl groups of urethane that merged with the Schiff base have appeared in the region of 1645-1619 cm 21 .…”

“…In all the PUs, sharp bands appearing between 3280 and 3384 cm 21 are due to the presence of hydrogen-bonded NÀ ÀH groups. 23 However, hydrogen-bonded carbonyl groups of urethane that merged with the Schiff base have appeared in the region of 1645-1619 cm 21 . NMR analysis suggests the disappearance of À ÀOH and À ÀNCO groups and the formation of urethane polymer chains.…”

“…Fluorescence spectra (F-2000, Hitachi, Tokyo, Japan) were also recorded in the wavelength range of 200-800 nm. FTIR spectral measurements were scanned between 400 and 4000 cm 21 with a Nicolet (Madison, WI) Impact 410 spectrophotometer to confirm the structures of the monomers and PU polymers in KBr pellets prepared under a hydraulic pressure of 400-600 kg/cm 2 . 1 H-NMR and 13 C-NMR spectra in CDCl 3 or dimethyl sulfoxide-d 6 (DMSO-d 6 ) were recorded on a Bruker 300-MHz NMR spectrophotometer (Silberstreifen, Rheinstetten, Germany).…”

“…20 Bands around 329-379 nm are assigned to azomethine p-p* transitions. 21 The emissions from these monomers 21 ) as well as the formation of several characteristic stretching vibrations due to NÀ ÀH, C¼ ¼O, CH¼ ¼N, and CÀ ÀH bonds. Hydrogen bonding in PUs is of great interest because it plays an important role 22 in determining the phase segregation.…”