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

Central European Journal of Chemistry - 2003
Mihaela Prajinaru1, Natalia Hurduc1, Silvia Alazaroaie2, Otilia Catanescu3, Nicolae Hurduc2
1Department of Physical and Theoretical Chemistry, “Al. I. Cuza” University IASI, IASI, Romania
2Department of Macromolecules, Technical University “Gh. Asachi” AISI, IASI, Romania
3Liquid Crystal Institute, Kent State University, Kent, USA

Tóm tắt

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.

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Central European Journal of Chemistry

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