Poly(<i>m</i>‐phenylene isophthalamides)‐containing nitro groups

Guijarro, Elena; Campa, José G. de la; Abajo, Javier de

doi:10.1002/pol.1984.170220632

Cited by 10 publications

(3 citation statements)

References 5 publications

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“…That was an unexpected behavior as a two step decomposition mechanism had been observed for other PIPA's containing substituents on the 5-position of the isophthalic unit. For example, when the substituent is a NO 2 group, two clear steps on the TGA curve have been detected, the first one corresponding to the loss of one NO 2 H molecule per repeating unit, [16] and that is also the case for other 5-substituted PIPA's. [17,18] Moreover, it has been well established that polymers containing chlorine are prone to thermally decompose through breaking down of the C1Cl linkage and elimination of gaseous HCl.…”

Section: Resultsmentioning

confidence: 99%

Thermal and Mechanical Properties of Halogen-Containing Aromatic Polyamides

Álvarez

Campa

Lozano

et al. 2001

Macromol. Chem. Phys.

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Aromatic polyamides containing fluorine, chlorine, bromine and iodine have been prepared, and they have been evaluated by their mechanical and thermal properties. The method of polycondensation in solution at low temperature revealed as a very appropriate route to attain high molecular‐weight halogen‐containing polyisophthalamides (PIPA's) from aromatic diamines and 5‐halogenoisophthaloyl chlorides. High glass transition temperatures (Tg) were found for the set of polymers, in the range 250–350°C, showing a clear dependence on the size of the halogen incorporated, with values of Tg growing up in the series F < Cl < Br < I. On the other hand, thermal resistance was slightly impaired by the presence of halogens, as revealed by thermogravimetric analysis (TGA). In the same way, the mechanical strength was poorer than that of the parent unmodified PIPA's, by about 20%. All the polymers exhibited a mechanical relaxation at sub‐ambient temperature, about –70°C, associated to local molecular motions involving halogen atoms.

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Section: Resultsmentioning

confidence: 99%

Thermal and Mechanical Properties of Halogen-Containing Aromatic Polyamides

Álvarez

Campa

Lozano

et al. 2001

Macromol. Chem. Phys.

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“…The glass transition and the foaming point were obtained (Table 9) from the thermal curves using methods recommended by Turi2* By analysis of the data obtained from a study of the thermogravimetric data in Table 10 a very interesting relationship between the structure of the main chain and thermal stability can be deduced. It was found that poly(nitroary1ates) 8 and 10 derived from 5-nitroisophthaloyl chloride (la) with hydroquinone (3) and 4,4'dihydroxydiphenyl (5) show the highest temperature of intensive decomposition and the lowest rate of weight loss relative to other poly(nitroary1ates) synthesized from the same diacid chloride (la). As was found previously, this stability may be attributed to the aromatic nature ofthese two polymers (8 and 10).…”

Section: Results a N D Discussionmentioning

confidence: 99%

Synthesis and Characterization of Some Novel Poly(nitroarylates)

Mansour

Kandil

Soliman

et al. 1992

Polymer International

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Various types of poly(nitroarylates) (8–17) were prepared using interfacial polycondensation (IPC) and solution polycondensation (SPC) of 5‐nitroiso‐phthaloyl chloride (la) and 2‐nitroterephthaloyl chloride (2a) with different bisphenols: hydroquinone (3), resorcinol (4), 4.4′‐dihydroxydiphenyl (5), 2,2‐bis(4‐hydroxyphenyl) propane (6) and bis(4‐hydroxyphenyl) sulfone (7). A nitro group was introduced in the polymeric chain in order to improve the properties, solubility and thermal stability of these polymers. Some of the factors affecting the IPC were studied, such as the effect of concentration of the initial components and the role of the solvent. The structures of the poly(nitroarylates) (8–17) were confirmed by elemental analysis, infrared and proton magnetic resonance spectrometry. Thermomechanical analysis (TMA) and thermogravimetric analysis (TGA) of the synthesized polymers were also studied.

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“…[1][2][3] Polyimides and other polyheterocycles containing nitro substituents have been also reported. Most of the polymers reported so far bear nitro groups placed on the ortho position with respect to the reactive functions, 4 -7 although there are a few examples of m-and p-oriented nitro groups, for instance polyamides with 5-nitroisophthalic acid 8 and p-nitrophenylquinoxalines. 9 A decrease of thermal stability has been observed in all cases, relative to the nonnitrated homologous polymers, caused by the breakdown of C Ar -NO 2 linkages, at lower temperature than the linkages in the main chain.…”

Section: Introductionmentioning

confidence: 98%

Novel polyimides withp-nitrophenyl pendant groups. Synthesis and characterization

Ayala

Lozano

Abajo

et al. 1999

J. Polym. Sci. A Polym. Chem.

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Polyimides derived from a new dianhydride with p‐nitrophenyl pendant groups have been synthesized and their properties compared with those of a reference series, without side groups. The polymers were obtained by combination of the novel monomer with aromatic diamines, in a two‐step procedure that involved the synthesis of poly(amic acid) or poly(amic silyl ester) intermediates and the cyclization of them to polyimides by thermal treatment. The introduction of the polar nitro groups caused significant increase of the Tgs. On the contrary, the thermal stability was reduced because of the breakdown of CAr—NO2 linkages around 400oC. A slight decrease in mechanical properties was observed, due to the bulkiness of the side groups, that also produced an important decrease in the strength of the β relaxation, as determined by dynamic mechanical analysis. The solubility of the current polyimides in organic solvents was as poor as that of the parent unsubstituted polymers. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3377–3384, 1999

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Poly(m‐phenylene isophthalamides)‐containing nitro groups

Cited by 10 publications

References 5 publications

Thermal and Mechanical Properties of Halogen-Containing Aromatic Polyamides

Thermal and Mechanical Properties of Halogen-Containing Aromatic Polyamides

Synthesis and Characterization of Some Novel Poly(nitroarylates)

Novel polyimides withp-nitrophenyl pendant groups. Synthesis and characterization

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