The effects of hydrogen bonding on the liquid crystalline behavior of semiflexible poly(urethane-ester)s

Michele Laus; Annino Sante Angeloni; Oriano Francescangeli; Giancarlo Galli; Emo Chiellini

doi:10.1002/masy.19971170131

The effects of hydrogen bonding on the liquid crystalline behavior of semiflexible poly(urethane-ester)s

Michele Laus
, Annino Sante Angeloni
, Oriano Francescangeli
, Giancarlo Galli
, Emo Chiellini

Research output: Contribution to journal › Article › peer-review

Abstract

The peculiar liquid crystalline behavior of two poly(urethane-ester)s TDI-C6C4 and TDI-C6C8 is reported. Evidence is provided of the formation of two nematic mesophases, a cybotactic nematic and a conventional nematic mesophase, in TDI-C6C8 and of one cybotactic nematic mesophase in TDI-C6C4. IR spectroscopy indicates that different hydrogen bonded and non-bonded structures occur with varying temperature. The transition from the nematic cybotactic mesophase to the nematic mesophase, or to the isotropic phase, is accompanied by a substantial decrease of the strength of the hydrogen bonds. This is also reflected in the dynamic-mechanical behavior of these poly(urethane-ester)s which is similar to the one of slightly crosslinked thermoreversible networks.

Original language	English
Pages (from-to)	275-280
Number of pages	6
Journal	Macromolecular Symposia
Volume	117
DOIs	https://doi.org/10.1002/masy.19971170131
Publication status	Published - May 1997
Externally published	Yes

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10.1002/masy.19971170131

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title = "The effects of hydrogen bonding on the liquid crystalline behavior of semiflexible poly(urethane-ester)s",

abstract = "The peculiar liquid crystalline behavior of two poly(urethane-ester)s TDI-C6C4 and TDI-C6C8 is reported. Evidence is provided of the formation of two nematic mesophases, a cybotactic nematic and a conventional nematic mesophase, in TDI-C6C8 and of one cybotactic nematic mesophase in TDI-C6C4. IR spectroscopy indicates that different hydrogen bonded and non-bonded structures occur with varying temperature. The transition from the nematic cybotactic mesophase to the nematic mesophase, or to the isotropic phase, is accompanied by a substantial decrease of the strength of the hydrogen bonds. This is also reflected in the dynamic-mechanical behavior of these poly(urethane-ester)s which is similar to the one of slightly crosslinked thermoreversible networks.",

author = "Michele Laus and Angeloni, \{Annino Sante\} and Oriano Francescangeli and Giancarlo Galli and Emo Chiellini",

year = "1997",

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doi = "10.1002/masy.19971170131",

language = "English",

volume = "117",

pages = "275--280",

journal = "Macromolecular Symposia",

issn = "1022-1360",

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T1 - The effects of hydrogen bonding on the liquid crystalline behavior of semiflexible poly(urethane-ester)s

AU - Laus, Michele

AU - Angeloni, Annino Sante

AU - Francescangeli, Oriano

AU - Galli, Giancarlo

AU - Chiellini, Emo

PY - 1997/5

Y1 - 1997/5

N2 - The peculiar liquid crystalline behavior of two poly(urethane-ester)s TDI-C6C4 and TDI-C6C8 is reported. Evidence is provided of the formation of two nematic mesophases, a cybotactic nematic and a conventional nematic mesophase, in TDI-C6C8 and of one cybotactic nematic mesophase in TDI-C6C4. IR spectroscopy indicates that different hydrogen bonded and non-bonded structures occur with varying temperature. The transition from the nematic cybotactic mesophase to the nematic mesophase, or to the isotropic phase, is accompanied by a substantial decrease of the strength of the hydrogen bonds. This is also reflected in the dynamic-mechanical behavior of these poly(urethane-ester)s which is similar to the one of slightly crosslinked thermoreversible networks.

AB - The peculiar liquid crystalline behavior of two poly(urethane-ester)s TDI-C6C4 and TDI-C6C8 is reported. Evidence is provided of the formation of two nematic mesophases, a cybotactic nematic and a conventional nematic mesophase, in TDI-C6C8 and of one cybotactic nematic mesophase in TDI-C6C4. IR spectroscopy indicates that different hydrogen bonded and non-bonded structures occur with varying temperature. The transition from the nematic cybotactic mesophase to the nematic mesophase, or to the isotropic phase, is accompanied by a substantial decrease of the strength of the hydrogen bonds. This is also reflected in the dynamic-mechanical behavior of these poly(urethane-ester)s which is similar to the one of slightly crosslinked thermoreversible networks.

UR - https://www.scopus.com/pages/publications/0642335841

U2 - 10.1002/masy.19971170131

DO - 10.1002/masy.19971170131

M3 - Article

SN - 1022-1360

VL - 117

SP - 275

EP - 280

JO - Macromolecular Symposia

JF - Macromolecular Symposia

ER -

The effects of hydrogen bonding on the liquid crystalline behavior of semiflexible poly(urethane-ester)s

Abstract

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