Disiloxane, hexamethyl-

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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

Quantity Value Units Method Reference Comment
liquid433.8J/mol*KN/ADzhafarov and Kuliev, 1986 
liquid433.84J/mol*KN/AScott, Messerly, et al., 1961 

Constant pressure heat capacity of liquid

Cp,liquid (J/mol*K) Temperature (K) Reference Comment
311.4298.15Dzhafarov and Kuliev, 1986T = 4 to 300 K. Cp(liq) = 275.5 - 34.48x10-2T + 21.7x10-1T2 (204 to 375 K).
311.37298.15Scott, Messerly, et al., 1961T = 12 to 371 K.

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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tboil373. ± 2.KAVGN/AAverage of 7 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple204.93KN/AScott, Messerly, et al., 1961, 2Uncertainty assigned by TRC = 0.02 K; TRC
Quantity Value Units Method Reference Comment
Tc518.7KN/AMcLure and Dickinson, 1976Uncertainty assigned by TRC = 0.51 K; TRC
Quantity Value Units Method Reference Comment
Pc19.25barN/AMcLure and Dickinson, 1976Uncertainty assigned by TRC = 0.10 bar; for sample see E.Dickinson and I.A.McClure, 1974-234; TRC

Enthalpy of vaporization

ΔvapH (kJ/mol) Temperature (K) Method Reference Comment
36.9315.EBFlaningam, 1986Based on data from 300. to 383. K.; AC
33.1327.N/ADitsent, Skorokhodov, et al., 1971Based on data from 293. to 361. K.; AC
36.324.EBScott, Messerly, et al., 1961Based on data from 309. to 411. K.; AC
34.6 ± 0.1332.CScott, Messerly, et al., 1961AC
33.1 ± 0.1351.CScott, Messerly, et al., 1961AC
31.3 ± 0.1373.CScott, Messerly, et al., 1961AC

Antoine Equation Parameters

log10(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Temperature (K) A B C Reference Comment
309.4 to 411.563.901991203.916-64.673Scott, Messerly, et al., 1961Coefficents calculated by NIST from author's data.

Enthalpy of fusion

ΔfusH (kJ/mol) Temperature (K) Reference Comment
11.920204.93Dzhafarov and Kuliev, 1986DH
11.9219204.93Scott, Messerly, et al., 1961DH
11.92204.9Domalski and Hearing, 1996AC

Entropy of fusion

ΔfusS (J/mol*K) Temperature (K) Reference Comment
58.18204.93Scott, Messerly, et al., 1961DH

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.

Dzhafarov and Kuliev, 1986
Dzhafarov, O.I.; Kuliev, A.M., Heat capacity and thermodynamic properties of disiloxanes, Dokl. Akad. Nauk. Azerb., 1986, SSR 42, 56-59. [all data]

Scott, Messerly, et al., 1961
Scott, D.W.; Messerly, J.F.; Todd, S.S.; Guthrie, G.B.; Hossenlopp, I.A.; Moore, R.T.; Osborn, A.; Berg, W.T.; McCullough, J.P., Hexamethyldisiloxane: chemical thermodynamic properties and internal rotation about the siloxane linkage, J. Phys. Chem., 1961, 65, 1320-1326. [all data]

Scott, Messerly, et al., 1961, 2
Scott, D.W.; Messerly, J.F.; Todd, S.S.; Guthrie, G.B.; Hossenlopp, I.A.; Moore, R.T.; Osborn, A.G.; Berg, W.T.; McCullough, J.P., Hexamethyldisiloxane: chemical thermodynamic properties and internal rotation about the siloxane linkage, J. Phys. Chem., 1961, 65, 1320-6. [all data]

McLure and Dickinson, 1976
McLure, I.A.; Dickinson, E., Vapor pressure of hexamethyldisiloxane near its critical point: corresponding-states principle for dimethylsiloxanes, J. Chem. Thermodyn., 1976, 8, 93-5. [all data]

Flaningam, 1986
Flaningam, Ora L., Vapor pressures of poly(dimethylsiloxane) oligomers, J. Chem. Eng. Data, 1986, 31, 3, 266-272, https://doi.org/10.1021/je00045a002 . [all data]

Ditsent, Skorokhodov, et al., 1971
Ditsent, V.E.; Skorokhodov, I.I.; Terent'eva, N.A.; Zolotareva, M.N., Russ. J. Phys. Chem., 1971, 45, 6, 901. [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]


Notes

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