The principle of corresponding states for liquid normal and branched alkanes

Klunder, H.; Hammers, W.E.; Ligny, C.L. De

doi:10.1007/bf01074865

Cited by 8 publications

(1 citation statement)

References 6 publications

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“…The indicator solutes used in this work were the following (numbers following the indicator name are those employed by Kamlet et al1 and for purposes of identification will be retained here): p-nitroanisole (1), 4-ethylnitrobenzene (4), TV.VV-diethyl-4-nitroaniline (6), 4-(dimethylamino)benzophenone (7), ethyl p-(dimethylamino)benzoate (9), MTV-dimethyl-p-nitroaniline (13), p-nitroaniline (14), 4-(dimethylamino)benzaldehyde (19), 2nitro-/>-toluidine (23), w-nitroaniline (28), Ar-methyl-2-nitroaniline (32), 2-nitroaniline (33), A,jV-dimethyl-4-nitrosoaniline (39), and 2-nitroanisole (45). Sources of the indicator solutes were Aldrich Chemical Co. (1, 4, 7, 9, 14, 19, 32, 39, 45), Eastman Chemical Co. (13, 28), and J. T. Baker Chemical Co. (33). N,N-Diethyl-4-nitroaniline was kindly provided by Dr. M. J. Kamlet (Naval Surface Weapons Center, Silver Spring, MD).…”

Section: Methodsmentioning

confidence: 99%

A study of solvatochromic linear energy relationships in a homologous series of n-alkanes and n-alkanenitriles

Brady¹,

Carr²

1985

J. Phys. Chem.

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Section: Methodsmentioning

confidence: 99%

A study of solvatochromic linear energy relationships in a homologous series of n-alkanes and n-alkanenitriles

Brady¹,

Carr²

1985

J. Phys. Chem.

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Lower critical solution temperature behavior of ethylene propylene copolymers in multicomponent solvents

Irani

Cozewith

1986

J of Applied Polymer Sci

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SynopsisThe lower critical solution temperature (LCST) locus for ethylene-propylene copolymers has been determined as a function of pressure in a variety of single and multicomponent solvents. The lower critical end-point temperature (LCEP), which is the intersection of the LCST locus with the vapor-pressure curve, was found to be predictable from the solvent density as previously established for singlecomponent solvents by Charlet and Delmas. Dissolving a lowmolecular hydrocarbon gas such as propylene in an alkane has a dramatic effect on lowering the LCEP, and can reduce phase-separation temperatures to levels at which this technique becomes attractive as a practical method for polymer recovery from diluents such as those used in solution polymerizations. Temperatures considerably above the LCEP are needed to minimize the residual polymer concentration in the solvent in the two-liquid-phase region. The solvent critical temperature must be approached for essentially complete elimination of the polymer from the solvent phase. The LCST locus was found to be a linear function of pressure for all of the systems investigated, and the slope of the line, d(LCST)/dP, could be well correlated as a function of solvent density and critical temperature. From the relationship between the LCEP and solvent density and the correlation for d(LCST)/dP, the location of the LCST locus can be readily predicted from a knowledge of solvent properties. INTRODUCTIONIt has long been recognized that most solutions of amorphous, nonpolar polymers in nonpolar solvents show a positive or endothermic heat of mixing, and that below a certain critical temperature (upper critical solution temperature or UCST) phase separation of the polymer solution occurs. This positive heat of mixing arises from the replacement of energetically preferred solvent-solvent and polymer-polymer contacts by unlike solvent-polymer contacts when a solution is formed.demonstrated that polymer-solvent systems also have a lower critical solution temperature (LCST), so that separation of the solution into multiple phases results from raising the solution temperature. Furthermore, since the LCST usually occurs at temperatures approaching the solvent critical temperature, pressures above atmospheric accompany it, and unlike the UCST, the LCST tends to be very pressure dependent. IRAN1 AND COZEWITHEssentially, as the system temperature approaches the critical temperature of the solvent, the solvent molecules tend toward a gas-like configuration, with all distinction between liquid and gas finally disappearing at the critical point. However, the very high-molecular weight polymer is far removed from its critical point and, consequently, undergoes no such 'dilation' effect as the temperature is raised. Accordingly, the polymer has a contracting effect on the solvent molecules, confining them to a more rigid matrix, and this lesser degree of spatial disorder for the solvent between the dilated and confined states results in a decreased entropy of mixing which leads to phase se...

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Pressure dependence of polymer chain conformational parameters

Bleha

1981

Makromol. Chem., Rapid Commun.

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The principle of corresponding states for liquid normal and branched alkanes

Cited by 8 publications

References 6 publications

A study of solvatochromic linear energy relationships in a homologous series of n-alkanes and n-alkanenitriles

A study of solvatochromic linear energy relationships in a homologous series of n-alkanes and n-alkanenitriles

Lower critical solution temperature behavior of ethylene propylene copolymers in multicomponent solvents

Pressure dependence of polymer chain conformational parameters

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