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Czasopismo
2003 | 1 | 4 | 387-401
Tytuł artykułu

Thermal and kinetic characteristics in non-isothermal conditions of some aromatic copolyethers containing an octomethylenic spacer

Treść / Zawartość
Warianty tytułu
Języki publikacji
EN
Abstrakty
EN
The paper presents a study of the thermal properties of some aromatic polyethers obtained by phase trasfer catalysis technique. The polymes were synthesized starting from 1,8-dichloro-octane and various bisphenols: 4,4′-dihydroxyazobenzene, 4,4′-dihydroxydiphenyl, bisphenol A and 2,7-dihydroxynaphthalene. Molecular simulations were performed in order to obtain supplementary information concerning the chain conformation and inter-chain interactions. The presence of azobenzenic moieties induces high phase transition values, situated near the thermal stability limit. Therefore, the thermogravimetrical study of these polymers is very important for establishing the temperature limits for DSC and optical microscopy studies. All the polymers present a good thermal stability situated above the isotropization values. In these circumstances no special precautions are necessary for the characterization methods of the liquid crystalline behavior. The kinetic characteristics suggest a similar degradation mechanism by successive reactions. The inter-chain interactions do not influence the thermostability of the samples if the polar surface of the polymer is situated below a certain value.
Wydawca

Czasopismo
Rocznik
Tom
1
Numer
4
Strony
387-401
Opis fizyczny
Daty
wydano
2003-12-01
online
2003-12-01
Twórcy
  • Department of Physical and Theoretical Chemistry, “Al. I. Cuza” University IASI, B-dul. Carol I No 11, 6600, IASI, Romania
  • Department of Physical and Theoretical Chemistry, “Al. I. Cuza” University IASI, B-dul. Carol I No 11, 6600, IASI, Romania
  • Department of Macromolecules, Technical University “Gh. Asachi” AISI, B-d Mangeron No 71, 700050, IASI, Romania
  • Liquid Crystal Institute, Kent State University, 44242-0001, Kent, OH, USA
  • Department of Macromolecules, Technical University “Gh. Asachi” AISI, B-d Mangeron No 71, 700050, IASI, Romania, nhurduc@ch.tuiasi.ro
Bibliografia
  • [1] S. Chandrasekhar: Liquid Crystals (Second Ed.), Cambridge University Press, New York, 1992.
  • [2] C. Carfagnia: Liquid Crystalline Polymers, Elsevier Science Inc., New York, 1994.
  • [3] G. Crawford and S. Zumer: Liquid Crystals in Complex Geometries, Taylor & Francis Ltd, London, 1996.
  • [4] G. Vertogen and W. H. de Jeu: Thermotropic Liquid Crystals, Fundamentals, Springer-Verlag, Berlin, Heidelberg, 1987.
  • [5] O. Catanescu, N. Hurduc, D. Scutaru I. Sava, I. Paraschiv, S. Alazaroaie: “Liquid Crystalline Polymers. 12. Thermal Behaviour of Some Aromatic Polyethers Containing Azobenzene and biphenyl Moieties”, Rev. Roum. de Chimie, Vol. 45, (2000), pp. 709–715.
  • [6] N. Hurduc, A. Daoudi, J.M. Buisine, V. Barboiu, C.I. Simionescu: “Liquid Crystalline Polymers- IV. A study of Thermal Behavior of Some Ternary Copolyethers, Containing 4,4′-dihydroxyazobenzene, Bisphenol A and 1,1-bis(4-hydroxyphenyl)ethane”, Eur. Polym. J., Vol. 34, (1997), pp. 123–125. http://dx.doi.org/10.1016/S0014-3057(97)00025-6[Crossref]
  • [7] O. Catanescu, N. Hurduc, D. Scutaru, A. Stoleru, C.I. Simionescu: “Liquid Crystalline Polymers 9. Synthesis and Thermal Behavior of Some Oligomers Containing a Diethyletheric spacer”, Die Angew. Macromol. Chem., Vol. 273, (1999), pp. 91–95. http://dx.doi.org/10.1002/(SICI)1522-9505(19991201)273:1<91::AID-APMC91>3.0.CO;2-M[Crossref]
  • [8] N. Hurduc, A. Creanga, D. Pavel, Natalia Hurduc: “Thermal properties and molecular simulation of some polyethers and copolyethers with semi-rigid chains”, Polym. Degrad. Stab., Vol. 70, (2000), pp. 277–282. http://dx.doi.org/10.1016/S0141-3910(00)00127-0[Crossref]
  • [9] E. Freeman and B. Carroll: J. Phys. Chem., Vol. 62, (1958), pp. 394. http://dx.doi.org/10.1021/j150562a003[Crossref]
  • [10] A.N. Coats and R. Redfern: Nature, Vol. 201, (1964), pp. 68. http://dx.doi.org/10.1038/201068a0[Crossref]
  • [11] Hyperchem 4.5, Hypercube Inc (licensed to M. Constantinescu).
  • [12] N. Hurduc, M. Prajinaru, B. Donse, D. Pavel, Natalia Hurduc: “Thermal behaviour and molecular modelling of some aromatic polyethers containing a hexamethylenic spacer”, Polym. Degrad. Stab., Vol. 72, (2001), pp. 441–445. http://dx.doi.org/10.1016/S0141-3910(01)00044-1[Crossref]
  • [13] A. Tarus, N. Hurduc, O. Catanescu, C. Cobzaru, N. Hurduc: “Phase transfer catalysis in polycondesation processes XXIV. On the thermal stability of some aromatic polyethers containing a propylenic spacer”, Polym. Degrad. Stab, Vol. 68, (2000), pp. 87–91. http://dx.doi.org/10.1016/S0141-3910(99)00169-X[Crossref]
  • [14] D. Pavel, J. Ball, S. Bhattacharya, R. Shanks, N. Hurduc and O. Catanescu: “Liquid Crystalline Polymers. Molecular Simulation of Monotropic and Enantiotropic Polymers Containing Azobenzene and Diphenyl Mesogens”, Computat. Theor. Polym. Sci., Vol. 11, (2001), pp. 303–318. http://dx.doi.org/10.1016/S1089-3156(00)00017-9[Crossref]
  • [15] D. Pavel, J. Ball, S Bhattacharya, R. Shanks, N. Hurduc: “Molecular Simulation of Thermophysical Properties of Aromatic Polymers Containing Oxetane Ring in the Main Chain”, J. Polym. Sci. Part B: Polym. Physics, Vol. 37, (1999), pp. 2334–2352. http://dx.doi.org/10.1002/(SICI)1099-0488(19990901)37:17<2334::AID-POLB5>3.0.CO;2-5[Crossref]
  • [16] D. Pavel, J. Ball, S. Bhattacharya, R. Shanks, V. Toace, V. Bulacovshi, N. Hurduc: “Molecular Simulation of Aromatic Polyesters Containing Oxetane Rings in the Main Chain”, Computat. Theory. Polym. Science, Vol. 1, (1999), pp. 1–9. http://dx.doi.org/10.1016/S1089-3156(98)00034-8[Crossref]
  • [17] D. Pavel, R. Shanks, S. Sangari, S. Alazaroaie, N. Hurduc: “Molecular Dynamics Simulation of Azobenzene Liquid Crystalline Polymers”, Macromole. Theory Simul., Vol. 12, (2003), pp. 127–141. http://dx.doi.org/10.1002/mats.200390013[Crossref]
  • [18] A. Creanga, G. Pokol, N. Hurduc, Cs. Novak, S. Alazaroaie, N. Hurduc: “Thermal Behavior of Primary, Degradation Mechanism of Some Aromatic Polyethers with Semi-Flexible Chain”, J. Them. Anal. Cal., Vol. 66, (2001), pp. 859–868. http://dx.doi.org/10.1023/A:1013108625929[Crossref]
  • [19] N. Hurduc, A. Creanga, G. Pokol, Cs. Novak, S. Alazaroaie, N. Hurduc: “The Degradation Mechanism Using TG-MS Technique of Some Aromatic Polyethers Containing Flexible Spacers”, J. Therm. Anal. Cal., Vol. 70, (2002), pp. 877–887. http://dx.doi.org/10.1023/A:1022268606503[Crossref]
  • [20] S. Alazaroaie, O. Catanescu, O. Dumitrica, V. Toader, N. Hurduc: “Liquid Crystalline Polymers. 10. The Influence of Flexible Spacer on Thermal Behaviour of Some Aromatic Polyethers”, Buletinul I.P.I., Vol. XLVI (L), (2000), pp. 65–72.
  • [21] S. Alazaroaie, O. Catanescu, V. Toader, E. Taran, N. Hurduc, D. Pavel, D. Scutaru: “Liquid Crystalline Polymers. 15. Synthesis and Thermal Behavior of Some Aromatic Polyethers Containing Different Spacers”, High Performance Polymers-submitted for publication.
  • [22] P. Budrugeac, E. Segal: “On the Compensation Effect at the Form of the Differential Conversion Function”, J. Therm. Anal. Cal., Vol. 56, (1998), pp. 269–283. http://dx.doi.org/10.1023/A:1010160930434[Crossref]
  • [23] P. Budrugeac, E. Segal: “On the Apparent Compensation Effect Found For Two Consecutive Reactions”, J. Therm. Anal. Cal., Vol. 62, (2000), pp. 227–235. http://dx.doi.org/10.1023/A:1010183316395[Crossref]
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.-psjd-doi-10_2478_BF02475224
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