TY - JOUR

T1 - Molecular and mesomorphic properties of alkylene-aromatic polyesters containing fluorinated spacers

AU - Rjumtsev, E. I.

AU - Sokolova, O. S.

AU - Lezov, A. V.

AU - Antonov, E. A.

AU - Mel'nikov, A. B.

AU - Bilibin, A. Yu

PY - 1997

Y1 - 1997

N2 - Two series of thermotropic liquid crystalline main-chain fluorine-containing polyesters, based on fluorinated alkylene diols and terephthaloyl-bis-(4-oxybenzoylchloride) and its analogue containing nitrogroup in the central phenylene ring were studied by polarizing microscopy, differential scanning calorimetry, viscometry, isothermic diffusion and electric birefringence methods. The upper limit of the fluorinated spacer length, when these polyesters lose their ability to form mesophase was found. It was established that the melting temperatures of the polyesters did not decrease with increasing number of CF2 groups in the spacer. The nematic textures of the investigated polymers were observed in cross polarizers. The differences in conformational and electrooptical properties of polyesters with fluoro- and hydrocarbon spacers were found. The dipole mechanism of the polyester molecules orientation in electric field was revealed. Two series of low-molecular-weight liquid crystalline compounds were synthesized to compare their properties with those of the polymers of similar structure. These esters exhibited a tendency to form smectic phase. The influence of the alkyl end group length on the mesomorphic properties of the esters was found.

AB - Two series of thermotropic liquid crystalline main-chain fluorine-containing polyesters, based on fluorinated alkylene diols and terephthaloyl-bis-(4-oxybenzoylchloride) and its analogue containing nitrogroup in the central phenylene ring were studied by polarizing microscopy, differential scanning calorimetry, viscometry, isothermic diffusion and electric birefringence methods. The upper limit of the fluorinated spacer length, when these polyesters lose their ability to form mesophase was found. It was established that the melting temperatures of the polyesters did not decrease with increasing number of CF2 groups in the spacer. The nematic textures of the investigated polymers were observed in cross polarizers. The differences in conformational and electrooptical properties of polyesters with fluoro- and hydrocarbon spacers were found. The dipole mechanism of the polyester molecules orientation in electric field was revealed. Two series of low-molecular-weight liquid crystalline compounds were synthesized to compare their properties with those of the polymers of similar structure. These esters exhibited a tendency to form smectic phase. The influence of the alkyl end group length on the mesomorphic properties of the esters was found.

KW - Alkylene-aromatic fluorocontainig polyesters

KW - Conformation

KW - Electrooptics

KW - Liquid crystals

KW - Melt

KW - Modeling compounds

KW - Phase transitions

KW - Relaxation

KW - Solution

UR - http://www.scopus.com/inward/record.url?scp=0031391916&partnerID=8YFLogxK

U2 - 10.1117/12.301291

DO - 10.1117/12.301291

M3 - Conference article

AN - SCOPUS:0031391916

VL - 3319

SP - 236

EP - 239

JO - Proceedings of SPIE - The International Society for Optical Engineering

JF - Proceedings of SPIE - The International Society for Optical Engineering

SN - 0277-786X

T2 - Liquid Crystals: Chemistry and Structure

Y2 - 3 March 1997 through 8 March 1997

ER -