1,3-Butadiene, 2-methyl-, homopolymer
- Monomer Formula: C5H8
- Monomer Molecular weight: 68.1170
- CAS Registry Number: 9003-31-0
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: ISOPRENE RUBBER; Rubber
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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 |
|---|---|---|---|---|---|
| S°solid,1 bar | 128.6 | J/mol*K | N/A | Warfield and Petree, 1965 | amorphous phase |
| S°solid,1 bar | 128.1 | J/mol*K | N/A | Bekkedahl and Matheson, 1935 | amorphous phase; From graphical integration of Cp data of crystal, entropy of fusion, and Cp data of amorphous above 284 K. |
Constant pressure heat capacity of solid
| Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 128.3 | 298.15 | Warfield and Petree, 1965 | amorphous phase; T = 14 to 320 K. A reexamination of 35BER/MAT. |
| 122.9 | 280. | Bekkedahl and Matheson, 1935 | T = 15 to 280 K. Values per C5H8 unit. |
| 128.1 | 298.15 | Bekkedahl and Matheson, 1935 | amorphous phase; T = 14 to 320 K. Value per C5H8 unit. |
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 by: Eugene S. Domalski and Elizabeth D. Hearing
Enthalpy of phase transition
| ΔHtrs (kJ/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
|---|---|---|---|---|---|
| 4.761 | 284. | crystaline | amorphous | Bekkedahl and Matheson, 1935 | Corrected for premelting, 255 to 284 K. Value per C5H8 unit. 'Fusion' actually transition to amorphous form. |
Entropy of phase transition
| ΔStrs (J/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
|---|---|---|---|---|---|
| 16.8 | 284. | crystaline | amorphous | Bekkedahl and Matheson, 1935 | Corrected |
References
Go To: Top, Condensed phase thermochemistry data, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Warfield and Petree, 1965
Warfield, R.W.; Petree, M.C.,
Thermodynamic properties of natural rubber and isoprene,
Die Makromol. Chemie, 1965, 84, 1-8. [all data]
Bekkedahl and Matheson, 1935
Bekkedahl, N.; Matheson, H.,
Heat capacity, entropy and free energy of rubber hydrocarbon,
J. Res., 1935, NBS 15, 503-515. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Cp,solid Constant pressure heat capacity of solid S°solid,1 bar Entropy of solid at standard conditions (1 bar) ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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