Dielectric and mechanical behaviour of ordered polyurethane networks based on mesogenic diol

Author

Ilavský, M. ; Valentová, H. ; Nedbal, J. ; Sedláková, Z.

Author_Institution

Fac. of Math. & Phys., Charles Univ., Prague, Czech Republic

fYear

1999

fDate

1999

Firstpage

585

Lastpage

588

Abstract

In this work we have studied the effect of ordered structure of polyurethane LCNs, based on poly(oxypropylene)triol (T), 2(4)-methyl-1,3-phenylene diisocyanate (Dr) and the mesogenic diol (D) cured at isotropic state, on the dielectric and dynamic mechanical behaviour. As was shown previously for uncrosslinked polymer from D and DI by DSC, X-ray scattering and polarizing microscopy, a nematic phase forms on cooling and freezes into the LC glassy state. On heating, the mesophase melts and, subsequently, a better-ordered smectic phase is formed at 110 °C, melting at 130°C

Keywords

dielectric polarisation; dielectric relaxation; liquid crystal phase transformations; liquid crystal polymers; smectic liquid crystals; 2(4)-methyl-1,3-phenylene diisocyanate; X-ray scattering; cooling; freezes; melts; mesogenic diol; ordered polyurethane networks; polarizing microscopy; poly(oxypropylene)triol; smectic phase; Chemicals; Cooling; Dielectric measurements; Electrochemical impedance spectroscopy; Frequency measurement; Polarization; Polymers; Shape measurement; Temperature dependence; X-ray scattering;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrets, 1999. ISE 10. Proceedings. 10th International Symposium on

Conference_Location

Athens

Print_ISBN

0-7803-5025-1

Type

conf

DOI

10.1109/ISE.1999.832115

Filename

832115