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Journal ArticleDOI

Synthesis and characterization of poly benzoylpropionamides

01 Jan 1982-European Polymer Journal (Pergamon)-Vol. 18, Iss: 2, pp 155-158
Abstract: Linear polyamides having viscosities in the range of 0.12–0.41 dl/g have been prepared from bisbenzoyl propionic acids and aromatic diamines by low temperature solution polycondensation in 80–85% yield. Their solubility characteristics were studied in various solvents e.g. DMF, DMAC, HMPT, H2SO4. These polyamides are amorphous in nature; their densities range from 1.2 to 1.8 g/cm3. Their thermal properties were examined by TGA and DTA. The two stage decomposition phenomenon observed in TGA is in agreement with the DTA results. The integral procedural decomposition temperatures were calculated and found to exceed 250 in almost all cases.

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Topics: Condensation polymer (50%)
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Journal ArticleDOI
Abstract: Several new aromatic-aliphatic cardopolyamides containing phenoxathiin and thianthrene derivatives were prepared by the direct polycondensation of 2,8-phenoxathiin-bis(γ-ketobutyric acid) (PA) or 2,7-thianthrene-bis(γ-ketobutyric acid) (TA) with 3,3-bis(4-aminophenyl phthalide) (PDA), 9,9-bis(4-aminophenyl fluorene (FDA), or 9,9-bis(4-aminophenyl) anthrone (ADA) in a triphenyl phosphite-pyridine system. The cardopolyamides were obtained in 80–95% yield and possessed viscosities in the range 0.90-1.35 dl/g. They showed better solubility and heat resistance than analogous noncardopolyamides derived from conventional diamines. All the polymers were characterised by IR spectra, density, solubility, crystallinity and thermal analysis. Integral procedural decomposition temperatures (IPDT) were calculated from the primary thermograms in the temperature range 100–650°C to give quantitative data regarding the thermal stabilities. The molecular weight and molecular weight distribution of the polyamides were determined by gel-permeation chromatography (GPC).

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3 citations


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Journal ArticleDOI
Abstract: Ordered aromatic polyamides and copolyamides were prepared by the polycondensation of terephthaloyl and isophthaloyl dichlorides with symmetrical diamines containing preformed amide linkages derived from unsymmetrical methyl—substituted aromatic diamines at low temperature. Thermal properties and solubilities of the ordered polyamides were compared with those of the corresponding random polyamides. There was little difference between thermal stabilities of the ordered polyamide and the corresponding random one, while the former was less soluble in organic solvents than the latter, depending on the extent of hydrogen bonding of the amide groups. The thermal stability of the alternating copolyamides containing both terephthaloyl and isophthaloyl groups as acid components was less than that of the corresponding homopolymers having either a terephthaloyl or an isophthaloyl group, and the solubility of the former resembled that of the corresponding ordered homopolysiophthalamides in accord with the extent of hydrogen bonding of the amide groups in both polymers.

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8 citations



Journal ArticleDOI
Abstract: The thermal behavior of random copolyamides which are used as model polymers with hydrogen bonds has been investigated by differential scanning calorimetry (DSC), x-ray diffraction, and infrared spectroscopy The quenched copolyamides have only halo patterns in their x-ray diffraction photographs A random copolymer of nylons 6, 66, and 610 (in a composition ratio of 3: 4: 3) was found to have 20% of unbonded amide groups immediately after quenching When the sample was kept at the glass transition temperature (20°C), no change in x-ray diffraction was observed after the treatment The free amide band in the infrared spectrum at 3450 cm-1, however, was decreased in intensity by keeping the sample at the glass transition temperature The transition peak height observed in a DSC curve also increased in the same experiment Large glass transition peaks were found in DSC curves after annealing of the random copolyamides in the vicinity of the glass transition temperature It is probable that the free amide groups in the amorphous chains were rearranged and formed new hydrogen bonds during the heat treatment at the glass transition temperature Packing and restriction of the amorphous chains due to the increase in hydrogen bonding seemed to increase the height of the transition peak in a DSC curve It is inferred from the above results that in the case of the random copolyamide, structures corresponding to a given enthalpy of the glassy state can be related to the number of hydrogen bonds

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6 citations


Journal ArticleDOI
Ronald Lee Dieck1, Louis Goldfarb1Institutions (1)
Abstract: A series of polyaryloxyphosphazene copolymers with the general formulas [NP(OC6H5)(OR)]n and [NP(OC6H4–4–OCH3)(OR)]n, where R = C6H4–4–CH3, C6H4–4–C2H5, C6H4–4–isoC3H7, C6H4–4–sec-C4H9, C6H4–4–tert–C4H9, C6H4–4–OCH3 or C6H4–4–OC4H9, have been prepared under anhydrous conditions. Copolymers as well as selected homopolymers were prepared by the reaction of polydichlorophosphazene with appropriate sodium aryloxides. Each of the polymers was characterized by elemental analysis, infrared spectroscopy, gel–permeation chromatography, and differential scanning calorimetry. Elemental analysis established the empirical formula for the polymers and showed that there were no residual PCl bonds left on the polymer backbone. Infrared spectroscopy indicated the presence of a phosphorus–nitrogen backbone with two aryloxy groups bonded to each phosphorus atom. The copolymers examined exhibited molecular weights of above 1 × 106. Polyaryloxyphosphazene copolymers were examined by differential scanning calorimetry and compared to several of the corresponding homopolymers. Glass transition temperatures ranged between −34 and +44°C for the polymers. The Kelley-Bueche equation was used to predict the glass transition temperatures of the copolymers. Close agreement was found between calculated and experimental values for most of the systems examined.

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6 citations


Journal ArticleDOI
Abstract: Six methyl-substituted wholly aromatic polyamides were synthesized from the reaction of 2,5-dimethylterephthaloyl chloride with p-phenylenediamine, its 2,5-dimethyl and 2-methyl derivatives, m-phenylenediamine, or its 2-methyl and 4-methyl derivatives by solution polycondensation at low temperature. The x-ray diffraction diagrams of the polyamides obtained exhibit crystal patterns. Density values range from 1.26 to 1.37 g/cm3. NMR spectra determined in concentrated H2SO4 solution are reported. Poly(2,5-dimethylterephthalamides) have lower thermal stability than the corresponding polyterephthalamides. The increase in solubility of polyamide by the introduction of the 2,5-dimethylterephthaloyl linkage is accompanied by a decrease in thermal stability. The effect of methyl substituents on thermal properties and solubility is discussed in terms of the packing of polymeric molecules and the extent of hydrogen bonding of the amide groups.

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5 citations