H. Kricheldorf, V. Döring, V. Eckhardt
Jun 1, 1988
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0
Influential Citations
20
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Journal
Macromolecular Chemistry and Physics
Abstract
2-Phenylthioterephthalic acid (1a) was prepared from thiophenol and dimethyl-2-nitroterephthalate. Homopolyesters of this diacid were prepared by transesterification with the diacetates of hydroquinone, methylhydroquinone, or 2,5-biphenyldiol. Copolyesters were prepared from equimolar amounts of hydroquinone and 4,4′-biphenyldiol or from hydroquinone and 4-hydroxybenzoic acid in various mole ratios. Inherent viscosities in the range of 0,4–2,0 dl/g were found. DSC-measurements indicate that in the case of (co)polyesters from hydroquinone the homopolyester has the highest glass-transition temperature (Tg = 181°C) and the highest melting point (Tm = 332°C). Also the homopolyesters from 1a and methyl- or phenylhydroquinone are crystalline. Furthermore, the homopolyesters from hydroquinone and 2-(p-tolylthio)terephthalic acid or 2-(4-chlorophenylthio)terephthalic acid were prepared. Microscopic observation under polarized light and WAXS-measurements confirmed that all polyesters form a nematic melt above Tg or Tm. In most cases the mesophase extents up to ca. 460°C where thermal decomposition prevents further observation. The homo- and copolyesters from 1 a and hydroquinone were also subjected to thermomechanical analyses by means of the penetration method.