02935nas a2200277   4500008004100000022001400041245015100055210006900206260007300275300001200348490000800360520184600368653000602214653005402220653004302274653002402317653003302341653001502374653002302389100001802412700001402430700003002444700002302474700002802497856013202525       2010                        eng d  a0921-510700aSynthesis and characterization of polyesters from 2,3-bis (4 `-hydroxy phenyl) quinoxaline and 2,3-bis (2 `-hydroxynaphthalene-6 `-yl) quinoxaline0 aSynthesis and characterization of polyesters from 23bis 4 hydrox  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a186-1920 v1683 a<p>Two bisphenols containing pendant, quinoxaline moiety; 2,3-bis (4'-hydroxy phenyl) quinoxaline (BHPQ) and 2,3-bis (2'-hydroxynaphthalene-6-yl) quinoxaline (BHNQ) were synthesized and characterized by FT-IR, (1)H, (13)C NMR and mass spectrometry. Aromatic polyesters and copolyesters were prepared by interfacial polymerization from BHPQ or BHNQ and isophthaloyl chloride or terephthaloyl chloride or a mixture of different mole proportions of (IPC + TPC). These polyesters and copolyesters were characterized by spectroscopic technique, viscosity measurement, solubility, thermal stability. DSC and XRD. Polymers had moderate to high molecular weights as evidenced by the inherent viscosities in the range 0.35-0.78 dL/g for BHPQ series and 0.27-0.52 dL/g for BHNQ series. BHPQ polyesters and copolyesters dissolved in m-cresol, NMP and conc. H(2)SO(4) whereas, BHNQ polyesters and copolyesters were readily soluble in NMP, DMAc, (TCE + phenol) and partly soluble in solvent like CHCl(3), pyridine, etc. Wide angle X-ray diffraction (WAXD) results showed that introduction of quinoxaline moiety into polymer chain and aromatic phenyl/rigid naphthyl structures lead to crystalinity. Differentional scanning calorimetry of BHNQ polyesters showed the glass transition temperatures in the range of 131-151 degrees C. BHPQ polyesters did not show any weight loss below 330 degrees C and retained 27-55% weight at 900 degrees C when investigated by TGA under nitrogen atmosphere demonstrating good thermal stability BHNQderived polyesters showed initial decomposition temperatures in range 211-234 degrees C. The structure-property relationships for the mentioned polyesters are analyzed, as these polyesters are of interest as materials for electronics, microelectronics and membrane separation. (C) 2009 Elsevier B.V. All rights reserved.</p>10a210a3-Bis (2 `-hydroxynaphthalene-6 `-yl) quinoxaline10a3-Bis (4 `-hydroxy phenyl) quinoxaline10aAromatic polyesters10aGlass transition temperature10asolubility10aThermal properties1 aPatil, V., B.1 aMedhi, M.1 aBhairamadgi, Nagendra, S.1 aWadgaonkar, P., P.1 aMaldar, Noormahamad, N.  uhttps://library.ncl.res.in/content/synthesis-and-characterization-polyesters-23-bis-4-hydroxy-phenyl-quinoxaline-and-23-bis-2-0