Orientation-Dependent Interactions in Polymer Systems. 5. Thermotropic Liquid Crystalline Transition of Tri-O-heptylcellulose

Akihiko Takada, Takeshi Fukuda, Junji Watanabe, Takeaki Miyamoto, Akihiko Takada, Junji Watanabe

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21 Citations (Scopus)

Abstract

Fairly narrow fractions of tri-O-heptylcellulose (THC) covering a wide range of degrees of polymerization (DP) were prepared and studied by viscometry and light scattering to determine the wormlike model parameters of the polymer to be q = 43.2 exp(-0.0050T) nm and ML = 880 nm-1, where q is the persistence length, ML is the shift factor, and T is the absolute temperature. The same fractions were studied with their thermal properties to determine the anisotropic-isotropic transition temperature Ti and transition entropy ΔS as a function of DP. Both Ti and ΔS increased with increasing DP to approach a limiting value for large enough DP. These trends were favorably compared with the predictions of the statistical models with the above-noted parameter values. It was shown that the main factor that causes the thermotropic transition and the chain-length dependence of Ti in bulk THC is the temperature-dependent flexibility of the polymer.

Original languageEnglish
Pages (from-to)3394-3400
Number of pages7
JournalMacromolecules
Volume28
Issue number9
DOIs
Publication statusPublished - Apr 1 1995
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

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