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Journal of Applied Polymer Science 01/2010; 116:1603. · 1.29 Impact Factor
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Journal of Macromolecular Science, Part A: Pure and Applied Chemistry. 01/2010; 47:154.
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Polymers for Advanced Technologies 01/2010; 21:767. · 2.01 Impact Factor
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Polymer for Advanced Technologies. 01/2009; 20:384.
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Journal of Macromolecular Science, Part A: Pure and Applied Chemistry. 01/2009; 46:484.
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Journal of Applied Polymer Science 01/2009; 112:3640. · 1.29 Impact Factor
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Journal of Applied Polymer Science 01/2009; 112:1226. · 1.29 Impact Factor
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Journal of Applied Polymer Science 01/2009; 113:1550. · 1.29 Impact Factor
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ABSTRACT: A series of novel fluorine containing aromatic polyamides were synthesized by the direct polycondensation of various fluorine containing aromatic diamines and commercially available 5-t-butyl isophthalic acid. These polyamides have good solubility in several organic solvents such as dimethylformamide, N,N-dimethylacetamide, 1-Methyl-2-pyrrolidone, dimethyl sulfoxide, and tetrahydrofuran. The synthesized polymers exhibited inherent viscosities up to 0.93 dL/g and Mw up to 1,52,000 with PDI of 2.49. The polyamides exhibited good thermal stability up to 489°C for 10% weight loss in nitrogen and high glass transition temperature up to 273°C. Dynamic mechanical analysis showed a very good retention of storage modulus up to the glass transition temperature. The tan δ peak value at 1 Hz was used to calculate the Tg and these values are in good agreement with differential scanning calorimetry data. The polyamide films were flexible with tensile strength up to 72 MPa, elongations at break up to 14%, and modulus of elasticity up to 1.39 GPa depending on the exact repeating unit structure. X-ray diffraction measurements indicate that these polyamides are semicrystalline. Rheology study showed same trend of melt viscosity behavior with different shear rate for all polymers. Water absorption study indicates the hydrophobic nature of the polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Journal of Applied Polymer Science 01/2008; 108(2):1356 - 1364. · 1.29 Impact Factor
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ABSTRACT: This paper describes the pervaporation study of benzene (Bz)/cyclohexane (Chx) (50/50 wt%) mixture through four structurally different semifluorinated aromatic poly(ether amide) (PEA) membranes (PEA I, PEA II, PEA III and PEA IV). The effects of variation of molecular structure on pervaporation performances towards Bz/Chx (50/50 wt%) mixture at three different temperatures (50, 60 and 70 °C) were studied and the results indicated that the membranes were benzene-selective in nature. The poly(ether amide), PEA IV containing cardo phenolphthalein anilide unit in the main chain showed the highest permselectivity value of 5.9 for a Bz/Chx mixture and the poly(ether amide), PEA III containing cardo fluorene moiety in the main chain showed highest permeation rate of 31.42 kg μm/m2 h in the series. The activation energies for pervaporation of Bz, Chx and Bz/Chx mixtures through the PEA membranes have been calculated from the Arrhenius equation.
Separation and Purification Technology 70(1):128-135. · 2.92 Impact Factor
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ABSTRACT: This manuscript describes the pervaporation study of benzene (Bz)/cyclohexane (Chx) mixture through four new semifluorinated poly(ether amide) (PEA) membranes. The polymers were prepared by phosphorylation polyamidation reaction of isophthalic acid (IA) and four structurally different semifluorinated diamine monomers (BTAPPI, BTAPPHI, BTAPPF, BTAPPPI). The synthesized polymers were characterized by elemental analyses, FT-IR, 1H and 13C NMR, TGA, DSC, DMA, WAXD and Rheology study. The polymers showed very good thermal stability associated with high glass transition temperatures (230–290 °C), good mechanical strength and preferential solubility in organic solvents. The membranes of these polymers showed higher permeation flux with comparable pervaporation selectivity in comparison to many other polymers reported earlier. An attempt has been taken to draw a structure property correlation of the chemical structures of the polymers with their pervaporation performance.
Journal of Membrane Science.
