Thermotropic copolyesters containing the 1,4‐cyclohexylenedimethylene spacer

Onwumere, Fidelis C.; Polk, Malcolm B.

doi:10.1002/pola.1986.080240918

Cited by 4 publications

(1 citation statement)

References 7 publications

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“…Our studies include the use of 1,4-cyclohexanedimethanol as flexible spacer unit. Previously, this compound has been used in connection with random terephthalic copolyesters of methyl-and chloro-substituted hydroquinones.10, 11 Studies of low molecular weight diester compounds in which one, two or all three of the benzene rings in mesogenic units are replaced by cyclohexane rings have been carried out.12 For these compounds, a decrease in melting point as well as a smaller decrease in clearing point is observed. Often, however, replacement of a benzene ring in a nematic low molecular weight compound by a trans-1,4-disubstituted cyclohexane ring may actually increase the clearing temperature,12 and this is observed unless13 the isotropization temperature is already high (£220 °C).…”

Section: Introductionmentioning

confidence: 99%

Thermotropic liquid crystal aromatic/cycloaliphatic polyesters with flexible spacers

Clausen¹,

Kops²,

Rasmussen³

et al. 1987

Macromolecules

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Thermotropic polyesters have been prepared from trans-1,4-cyclohexanedicarbonyl chloride and , -alkanediyl 4-hydroxybenzoates with a variable number of methylene carbons in the alkane chain. The melt transitions generally are lower than those of the corresponding thermotropic fully aromatic triad polyesters. The presence of cycloaliphatic groups in the mesogenic triad leads to enhanced solubility which has allowed an estimation, by GPC measurements, of the molecular weights which are rather low, corresponding to degrees of polymerization of no more than 3 or 4. The inherent viscosities for the polymers, however, are comparable to values published for other thermotropic polyesters with flexible spacers. For a polyester prepared from trans-1,4-cyclohexanedicarbonyl chloride and 4-hydroxybenzoic acid trans-1,4-cyclohexanediylbis-(methylene) ester no mesophase could be observed upon melting.

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Section: Introductionmentioning

confidence: 99%