ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
There are investigated the relations between the liquid compositions in the two phases formed when a polymer equilibrates in a mixed solvent. By imposing the simplifyng constraint that all of the polymer be located in one of the two phases, an expression for the equilibrium composition ratio, R = (ϕ1/ϕ2)/(v1/v2), is obtained through use of the customary expressions for the free energy of polymer solutions: \documentclass{article}\pagestyle{empty}\begin{document}$ \ln R = 2_{\chi 12^\varepsilon} + [\chi 12(v_2 - v_1) + l_{\chi 23} - \chi 13]\varphi _3 - (1 - l)\ln (1 - \varphi _3 - \varepsilon /v_2) $\end{document} Here subscripts 1, 2, and 3 refer to the two liquids and the polymer, respectively, χ is a free energy parameter, l is the ratio V1/V2 of the molar volumes of the two liquids, ϕ and v represent the volume fraction in the ternary and binary phases, respectively, and ∊ is an auxiliary variable relating ϕ and v for the two liquid components. Certain consequences of the equilibrium composition relationship are examined, and there are suggested possible applications to diffusion, light scattering, and solubility. The results of analysis of the two phases formed when crosslinked natural rubber equilibrates with the mixed solvent pairs: benzene-nitromethane and m-xylene-nitromethane confirm the form of the equilibrium composition relationship, and the values for the free energy parameters required to represent the data for these ternary systems appear to be reasonable.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1954.120147502
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