Home About us Contact
|
Home About us Contact | ||
|
|
||
Various Aromatic Diamines (various + aromatic_diamine)
Selected AbstractsSynthesis and properties of novel soluble polyamides having ether linkages and laterally attached p -terphenyl unitsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2004Sheng-Huei Hsiao Abstract A new ether-bridged aromatic dicarboxylic acid, 2,,5,-bis(4-carboxyphenoxy)- p -terphenyl (3), was synthesized by the aromatic fluoro-displacement reaction of p -fluorobenzonitrile with 2,,5,-dihydroxy- p -terphenyl in the presence of potassium carbonate, followed by alkaline hydrolysis. A set of new aromatic polyamides containing ether and laterally attached p -terphenyl units was synthesized by the direct phosphorylation polycondensation of diacid 3 with various aromatic diamines. The polymers were produced with high yields and moderately high inherent viscosities (0.44,0.79 dL/g). The polyamides derived from 3 and rigid diamines, such as p -phenylenediamine and benzidine, and a structurally analogous diamine, 2,,5,-bis(4-aminophenoxy)- p -terphenyl, were semicrystalline and insoluble in organic solvents. The other polyamides were amorphous and organosoluble and could afford flexible and tough films via solution casting. These films exhibited good mechanical properties, with tensile strengths of 91,108 MPa, elongations to break of 6,17%, and initial moduli of 1.95,2.43 GPa. These polyamides showed glass-transition temperatures between 193 and 252 °C. Most of the polymers did not show significant weight loss before 450 °C, as revealed by thermogravimetric analysis in nitrogen or in air. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4056,4062, 2004 [source] Synthesis and properties of organosoluble poly(amide imide imide)s based on tetraimide dicarboxylic acid condensed from 4,4,-(hexafluoroisopropylidene)diphthalic anhydride, 4,4,-oxydianiline, and trimellitic anhydride and various aromatic diaminesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2002Chin-Ping Yang Abstract A novel tetraimide dicarboxylic acid was synthesized with the ring-opening addition of 4,4,-(hexafluoroisopropylidene)diphthalic anhydride, 4,4,-oxydianiline, and trimellitic anhydride in a 1/2/2 molar ratio in N -methyl-2-pyrrolidone followed by azeotropic condensation to tetraimide dicarboxylic acid. A series of poly(amide imide imide)s (PAIIs) with inherent viscosities of 0.8,1.1 dL/g were prepared from tetraimide dicarboxylic acid with various aromatic diamines by direct polycondensation. Most of the PAIIs were readily soluble in a variety of amide polar solvents and even in less polar m -cresol and pyridine. Solvent-cast films had tensile strengths ranging from 99 to 106 MPa, elongations at break ranging from 8 to 13%, and initial moduli ranging from 2.0 to 2.3 GPa. The glass-transition temperatures of these PAIIs were recorded at 244,276 °C. They had 10% weight losses at temperatures above 520 °C in air or nitrogen atmospheres. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1092,1102, 2002 [source] Synthesis and properties of new aromatic polyimides based on 2,2,-dibromo-4,4,,5,5,-benzophenone tetracarboxylic dianhydridePOLYMER INTERNATIONAL, Issue 8 2004Ahmad Banihashemi Abstract New polyimides with enhanced thermal stability and high solubility were synthesized in common organic solvents from a new dianhydride, 2,2,-dibromo-4,4,,5,5,-benzophenone tetracarboxylic dianhydride (DBBTDA). DBBTDA was used as monomer to synthesize polyimides by using various aromatic diamines. The polymers were characterized by IR and NMR spectroscopy and elemental analysis. These polyimides had good inherent viscosities in N -methyl-2-pyrrolidinone (NMP) and also high solubility and excellent thermo-oxidative stability, with 5 % weight loss in the range 433 to 597 °C. Copyright © 2004 Society of Chemical Industry [source] Synthesis and characterization of novel aromatic poly(amide-imide)s derived from 2,2,-bis(4-trimellitimidophenoxy)biphenyl or 2,2,-bis(4-trimellitimidophenoxy)-1,1,-binaphthyl and various aromatic diaminesPOLYMER INTERNATIONAL, Issue 7 2003Ahmad Banihashemi Abstract New aromatic diimide-dicarboxylic acids having kinked and cranked structures, 2,2,-bis(4-trimellitimidophenoxy)biphenyl (2a) and 2,2,-bis(4-trimellitimidophenoxy)-1,1,-binaphthyl (2b), were synthesized by the reaction of trimellitic anhydride with 2,2,-bis(4-aminophenoxy)biphenyl (1a) and 2,2,-bis(4-aminophenoxy)-1,1,-binaphthyl (1b), respectively. Compounds 2a and 2b were characterized by FT-IR and NMR spectroscopy and elemental analyses. Then, a series of novel aromatic poly(amide-imide)s were prepared by the phosphorylation polycondensation of the synthesized monomers with various aromatic diamines. Owing to structural similarity, and a comparison of the characterization data, a model compound was synthesized by the reaction of 2b with aniline. The resulting polymers with inherent viscosities of 0.58,0.97 dl g,1 were obtained in high yield. The polymers were fully characterized by FT-IR and NMR spectroscopy. The ultraviolet ,max values of the poly(amide-imide)s were also determined. The polymers were readily soluble in polar aprotic solvents. They exhibited excellent thermal stabilities and had 10% weight loss at temperatures above 500 °C under a nitrogen atmosphere. Copyright © 2003 Society of Chemical Industry [source] | ||||||||||