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Different Diamines (different + diamine)
Selected AbstractsDehydration of benzene through fluorine containing aromatic polyamide membrane by pervaporationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008P. K. Gutch Abstract A series of soluble polyamides were synthesized by direct polycondensation of the 5- tert -butyl isophthalic acid with different diamines. Solution (20%) of the polymers in suitable solvents was used to cast the membranes. The membranes showed selectivity toward the benzene (Bz) in a mixture of Bz/water (H2O). Water affinity of the membrane was found to be lower than that of Bz. The polyamide incorporating hexafluoro isopropylidene moiety was promising for the dehydaration of Bz and breaking of Bz/H2O azeotrope. The polymers exhibited inherent viscosities, ranging from 0.40 to 0.92 dL/g and 10% weight loss in synthetic air up to 474°C. Glass transition temperature measured by DSC and DMA reached up to 258°C. The membranes were pale yellow in appearance having tensile strength up to 85 MPa, modulus of elasticity up to 2.6 GPa, and elongation at break up to 9.5%, depending upon the exact repeating unit structure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis, characterization, and comparison of properties of novel fluorinated poly(imide siloxane) copolymersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008Anindita Ghosh Abstract Four new poly(imide siloxane) copolymers were prepared by a one-pot solution imidization method at a reaction temperature of 180°C in ortho -dichlorobenzene as a solvent. The polymers were made through the reaction of o -diphthaleic anhydride with four different diamines,4,4,-bis(p -aminophenoxy-3,3,-trifluoromethyl) terphenyl, 4,4,-bis(3,-trifluoromethyl- p -aminobiphenyl ether)biphenyl, 2,6-bis(3,-trifluoromethyl- p -aminobiphenyl ether)pyridine, and 2,5-bis(3,-trifluoromethyl- p -aminobiphenylether)thiopene,and aminopropyl-terminated poly dimethylsiloxane as a comonomer. The polymers were named 1a, 1b, 1c, and 1d, respectively. The synthesized polymers showed good solubility in different organic solvents. The resulting polymers were well characterized with gel permeation chromatography, IR, and NMR techniques. 1H-NMR indicated that the siloxane loading was about 36%, although 40 wt % was attempted. 29Si-NMR confirmed that the low siloxane incorporation was due to a disproportionation reaction of the siloxane chain that resulted in a lowering of the siloxane block length. The films of these polymers showed low water absorption of 0.02% and a low dielectric constant of 2.38 at 1 MHz. These polyimides showed good thermal stability with decomposition temperatures (5% weight loss) up to 460°C in nitrogen. Transparent, thin films of these poly(imide siloxane)s exhibited tensile strengths up to 30 MPa and elongations at break up to 103%, which depended on the structure of the repeating unit. The rheological properties showed ease of processability for these polymers with no change in the melt viscosity with the temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Preparation of poly(amic acid) and polyimide derived from 3,3,,4,4,-benzophenonetetracarboxylic dianhydride with different diamines by microwave irradiationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Quantao Li Abstract Polycondensation-type poly(amic acid) (PAA) was synthesized with 3,3,,4,4,-benzophenonetetracarboxylic dianhydride as a dianhydride monomer and 4,4,-diaminodiphenylmethane and 4,4,-oxydianiline as diamine monomers under microwave irradiation in dimethylformamide. Then, PAA was used to make polyimide (PI) by imidization at a low temperature. The structure and performance of the polymers were characterized with Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), viscosity, X-ray diffraction (XRD), and thermogravimetry (TG) curve analyses. The FTIR spectra of the polymers showed characteristic peaks of PI around 1779 and 1717 cm,1. The 1H-NMR spectrum of PAA indicated a singlet at 6.55 ppm assigned to NHCO and a singlet at 10.27 ppm assigned to carboxylic acid protons. The XRD spectrum demonstrated that the obtained PI had a low-order aggregation structure with a d -spacing of 0.5453 nm. The TG results revealed that the PI was thermally stable with 10% weight loss at 565°C in an N2 atmosphere. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] Preparation and properties of new thermally stable poly(ether imide amide)sPOLYMER INTERNATIONAL, Issue 8 2004Shahram Mehdipour-Ataei Abstract 2,6-Bis(4-aminophenoxy)pyridine was prepared via reaction of 4-aminophenol with 2,6-dichloropyridine in the presence of potassium carbonate. Reaction of the diamine with two mol of trimellitic anhydride afforded a diacid with preformed imide structures. Poly(ether imide amide)s were prepared by polycondensation reactions of the diacid with different diamines in the presence of triphenyl phosphite. All the monomers and polymers were fully characterized and the physical properties of the polymers including solution viscosity, thermal stability, thermal behavior and solubility were studied. Thermal analysis data showed the polymers to have high thermal stability. Copyright © 2004 Society of Chemical Industry [source] |