Flory-Huggin’s interaction parameter

The Flory-Huggin S Interaction Parameter. These ideas, based on a study of polymer miscibility, have been applied to plasticizers according to the following equation in which V is the molar volume of the plasticizer, obtained from molar mass figures and density values at TV, and % represents the interaction parameter (11). 

Liquid water as contacting medium (dealt as a solvent) interacts with polymer molecules in different degrees some dissolve polymers, some swell polymers, and some are merely adsorbed at the polymer/water interface with no significant alteration of physical properties of polymers. The enthalpy term of the interaction could be represented by Flory-Huggins s interaction parameter x- In order to distinguish the molecular interaction from the interfacial interaction, the molecular interaction could be termed x interaction and the interfacial interaction y interaction. When a solid polymer is in contact with water (solvent), the extent of x interaction depends on the hydrophilicity or hydrophobicity of the polymer. However, the interfacial phenomena generally cannot be interpreted by molecular level parameters that describe the bulk phase of a polymer such as hydrophilicity or hydrophobicity. 

The Flory-Huggin s interaction parameter, x, is defined by the equation... 

Roult s law is known to fail for vapour-liquid equilibrium calculations in polymeric systems. The Flory-Huggins relationship is generally used for this purpose (for details, see mass-transfer models in Section 3.2.1). The polymer-solvent interaction parameter, xo of the Flory-Huggins equation is not known accurately for PET. Cheong and Choi used a value of 1.3 for the system PET/EG for modelling a rotating-disc reactor [113], For other polymer solvent systems, yj was found to be in the range between 0.3 and 0.5 [96],... 

Ky is the Flory-Huggins interaction parameter between the i and j monomers. In Eq. 6.6, the matrices have a dimension (m) (m). We note that the s-depen-dence of the excluded volume matrix is solely determined by the contribution of the bare susceptibility yoo(Q> ) he invisible matrix component 0 . Finally, combining Eq. 6.6 with Eq. 6.1 the response function in the interacting system is given by ... 

In addition to the solubility parameter model to treat SEC adsorption effects, an approach based on Flory-Huggins interaction parameters has also been proposed (24-27). For an excellent review of both mechanisms, see reference 28.- A general treatment of polymer adsorption onto chromatographic packings can be found in Belenkii and Vilenchik s recent book (29). 

Let us analyze now the results for the general case when network swells in a solution of linear polymers. Let p, C, be, respectively, the volume fractions of linear polymer and low-molecular solvent in external solution Xps. Xn and Xnp are the Flory-Huggins interaction parameters between linear polymer (P), network polymer (N) and solvent (S). 

Our discussion here explores active connections between the potential distribution theorem (PDT) and the theory of polymer solutions. In Chapter 4 we have already derived the Flory-Huggins model in broad form, and discussed its basis in a van der Waals model of solution thermodynamics. That derivation highlighted the origins of composition, temperature, and pressure effects on the Flory-Huggins interaction parameter. We recall that this theory is based upon a van der Waals treatment of solutions with the additional assumptions of zero volume of mixing and more technical approximations such as Eq. (4.45), p. 81. Considering a system of a polymer (p) of polymerization index M dissolved in a solvent (s), the Rory-Huggins model is... 

The Flory-Huggins model differs from the regular solution model in the inclusion of a nonideal entropy term and replacement of the enthalpy term in solubility parameters by one in an interaction parameter x- This parameter characterizes a pair of components whereas each S can be deduced from the properties of a single component. 

It has been shown (3) using Scott s ternary solution treatment (25) of the Flory-Huggins theory, that the overall interaction parameter between the volatile probe (1) and the binary stationary phase (2,3) is given by... 

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