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p-n-Octadecyloxybenzoic acid

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Condensed phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of solid

Cp,solid (cal/mol*K) Temperature (K) Reference Comment
34.7320.Ikeda and Hatakeyama, 1976T = 320 to 420 K. Value is unsmoothed experimental datum for c,I phase.

Phase change data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Kenneth Kroenlein director
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tfus378.KN/AHerbert, 1967Smectic liquid crystal phase; Uncertainty assigned by TRC = 1. K; TRC

Temperature of phase transition

Ttrs (K) Initial Phase Final Phase Reference Comment
342.5crystaline, III, c,IIIliquid, smectic transition temperatureIkeda and Hatakeyama, 1976DH

Enthalpy of phase transition

DeltaHtrs (kcal/mol) Temperature (K) Initial Phase Final Phase Reference Comment
16.085379.5crystaline, IliquidIkeda and Hatakeyama, 1976DH
9.2973371.0crystaline, IIliquidIkeda and Hatakeyama, 1976DH
3.1788408.5liquidliquidIkeda and Hatakeyama, 1976DH

Entropy of phase transition

DeltaStrs (cal/mol*K) Temperature (K) Initial Phase Final Phase Reference Comment
42.3379.5crystaline, I, c,Iliquid, smectic transitionIkeda and Hatakeyama, 1976DH
25.1371.0crystaline, II, c,IIliquid, smectic transitionIkeda and Hatakeyama, 1976DH
7.9408.5liquid, Smecticliquid, isotropicIkeda and Hatakeyama, 1976DH

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


References

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Ikeda and Hatakeyama, 1976
Ikeda, M.; Hatakeyama, T., Thermal studies on the phase transition of p-n-Octadecyloxybenzoic acid (Part I), Mol. Cryst. Liq. Cryst., 1976, 33, 201-212. [all data]

Herbert, 1967
Herbert, A.J., Transition temperatures and transition energies of the p-n-alkoxy benzoic acids, from n-propyl to n-octadecyl, Trans. Faraday Soc., 1967, 63, 555, https://doi.org/10.1039/tf9676300555 . [all data]


Notes

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