@article { ISI:000271108500027, title = {Synthesis and thermal properties of soluble silicon containing phenylated aromatic-aliphatic polyamides}, journal = {Journal of Thermal Analysis and Calorimetry}, volume = {98}, number = {2}, year = {2009}, month = {NOV}, pages = {539-545}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Aromatic polyamides find many applications in diverse and critical areas due to their high thermal stability coupled with high mechanical properties. However most of such aramides are difficult to fabricate because of their limited solubility and high melting temperature. Improvements in processability have been reported by incorporating bulky pendant groups and aliphatic spacer groups. Similarly to improve the solubility of polymers approaches of incorporating silicon in main polymer chain and co-polymerization techniques were useful. We report the synthesis and characterization of a series of phenylated silicon containing aromatic-aliphatic polyamides from a mixture of 2, 5-bis (4-carboxy methylene phenyl)-3, 4-diphenyl thiophene (CMPDT) and bis-(4-carboxy phenyl) dimethyl silane (BCPDS) in various mole proportions, with commercial aromatic diamine. Thus a series of novel co-polyamides having pendant phenyl groups, methylene spacer and silicon moiety was prepared by judicious combination of (CMPDT); BCPDS and aromatic diamine; bis-(4-aminophenyl) ether (ODA), by direct polycondensation using Yamazaki{\textquoteright}s phosphorylation method. These high molecular mass polyamides were obtained in high (89-98\%) yields and had viscosities in the range of 0.23-0.57 dL/g in DMAc. Polyamides showed improved solubility in polar aprotic solvents, like NMP, DMAc, DMSO and DMF; had high thermal stability; with no mass loss below 335 A degrees C.

}, keywords = {2, 4-diphenyl thiophene, 5-bis (4-carboxy methylene phenyl)-3, bis-(4-amino phenyl) ether, bis-(4-carboxy phenyl) dimethyl silane, Copolyamides, solubility, thermal stability}, issn = {1388-6150}, doi = {10.1007/s10973-009-0286-y}, author = {Ghanwat, A. A. and Sayyed, M. M. and Wadgaonkar, P. P. and Maldar, Noormahamad N.} } @article { ISI:000278307300032, title = {Synthesis and characterization of polyesters from 2,3-bis (4 {\textquoteleft}-hydroxy phenyl) quinoxaline and 2,3-bis (2 {\textquoteleft}-hydroxynaphthalene-6 {\textquoteleft}-yl) quinoxaline}, journal = {Materials Science and Engineering B-Advanced Functional Solid-State Materials}, volume = {168}, number = {1-3, SI}, year = {2010}, note = {Conference on Specialty Advanced Materials and Polymers for Aerospace and Defense and Applications (SAMPADA-2008), Mat Res Soc Singapore, Singapore, SINGAPORE, JUL 03-08, 2005}, month = {APR}, pages = {186-192}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Two bisphenols containing pendant, quinoxaline moiety; 2,3-bis (4{\textquoteright}-hydroxy phenyl) quinoxaline (BHPQ) and 2,3-bis (2{\textquoteright}-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.

}, keywords = {2, 3-Bis (2 {\textquoteleft}-hydroxynaphthalene-6 {\textquoteleft}-yl) quinoxaline, 3-Bis (4 {\textquoteleft}-hydroxy phenyl) quinoxaline, Aromatic polyesters, Glass transition temperature, solubility, Thermal properties}, issn = {0921-5107}, doi = {10.1016/j.mseb.2009.12.036}, author = {Patil, V. B. and Medhi, M. and Bhairamadgi, Nagendra S. and Wadgaonkar, P. P. and Maldar, Noormahamad N.} } @article { ISI:000291605900010, title = {Polyamides containing quinoxaline moiety}, journal = {Journal of Polymer Research}, volume = {18}, number = {4}, year = {2011}, month = {JUL}, pages = {549-557}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

A new quinoxaline moiety containing aromatic diamine; 2,3-bis[4-(4-aminophenoxy)phenyl]quinoxaline (APQ) was synthesized starting from 4-methoxybenzaldehyde and was characterized by IR, (1)H, (13)C NMR and Mass spectrometry. Five new polyamides were synthesized by polycondensation of various aliphatic diacid / aromatic diacids namely, azelaic acid, bis(4-carboxyphenyl)dimethylsilane, 4,4{\textquoteright}-oxybis(benzoicacid), isophthalic acid and terephthalic acid with APQ by Yamazaki{\textquoteright}s phosphorylation method using triphenyl phosphite as condensing agent. The polyamides were characterized by IR spectroscopy, solubility tests, inherent viscosity, X-ray diffraction technique, differential scanning colorimetry and thermogravimetric analysis. The polyamides had inherent viscosities in the range 0.39-0.45 dL/g in N, N-dimethylacetamide at 30 +/- 0.1 A degrees C. The polyamides were soluble in polar aprotic solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone. X-Ray diffraction studies showed that polyamides were amorphous in nature. The polyamides showed glass transition temperatures in the range 104-205 A degrees C, according to differential scanning calorimetry. Thermogravimetric analysis exhibited initial decomposition temperatures above 348 A degrees C; indicating that these polyamides possessed excellent thermal stability.

}, keywords = {polyamides, Quinoxaline, solubility, Thermal properties, XRD}, issn = {1022-9760}, doi = {10.1007/s10965-010-9448-7}, author = {Patil, Vidyadhar B. and Sayyed, Maheboob M. and Mahanwar, Prakash A. and Wadgaonkar, Prakash P. and Maldar, Noormahamad N.} }