Benzene, Flory interaction parameters

Flory Interaction Parameters for Illinois Number 6 Coal Extracts and Benzene... 

We have recently extended the Flory model to deal with nonpolar, two-solvent, one polymer soltulons (13). We considered sorption of benzene and cyclohexane by polybutadiene. As mentioned earlier, a binary Interaction parameter Is required for each pair of components In the solution. In this Instance, we required Interaction parameters to represent the Interactions benzene/cyclohexane, benzene/polybutadlene, and cyclohexane/ polybutadiene. 

The above values are applicable only in the limiting case of infinite dilution. The interaction parameter varies with the volume fraction of polymer network as has been demonstrated for the PDMS-benzene system by Flory (47) and PDMS-methyl ethyl ketone, PDMS-methyl isobutyl ketone, PDMS-ethyl-n-butyl ketone, and PDMS-diisobutyl ketone by Shiomi et al. (48). Theoretically calculated and experimentally observed values of X as a function of volume fraction of polymer are given for PDMS in alkanes, aromatic hydrocarbons, and dimethyl siloxane oligomers by Gottlieb and Herskowitz (49). In the case of PDMS-alkanes, x was practically independent of the volume fraction of polymer. 

Fig. 3.10. Comparison of the predictions of the equation-of-state theory (full line) with the results ( ) of experiment for the concentration dependence of the interaction parameter of poly(isobutylene) in benzene at 2S °C (after Eichinger and Flory, 1968).

Figure 6-4. Dependence of the Flory-Huggins interaction parameter, x, on volume fraction, 2, of the polymer for poly(styrene) in cyclohexane and chloroform and for m-l,4-poly(isoprene) in benzene as well as for cellulose nitrate in acetone.

Figure 1. Examples for the variation of the Flory-Huggins interaction parameter, Cl 4), with the volume fraction tpi of polymer for the systems benzene/polyOsobutylene) (PIB), n-pentane/PIB and cyclohexane/PIB at the indicated temperatures.

FIGURE 2.3 The interaction parameter X as a function of polymer volume fraction Vj for various PDMS networks of different structures and modulus swollen in benzene. The data points are calculated from the swelling results using Equation 2.17. The line represents data obtained for solutions of uncross-linked PDMS chains in benzene. (Data from Flory, P. J., and Shih, H., Macmmolecules, 5,761,1972 Patel, S. K., Malone, S., Gilmor, J. R., and Colby, R. H., Macwmolecules, 25, 5241, 1992.)... 

Figure 9.5 Influence of composition on the polymer-solvent interaction parameter. Experimental values of the interaction parameter Xi are plotted against the volume ftaction (j)2 of polymer. Data for polydimethylsiloxane (M = 3850) in benzene (A), polystyrene in methyl ethyl ketone ( ), and polystyrene in toluene (O) are based on vapor-pressure measurements. Those for rubber in benzene (T) were obtained using vapor-pressure measurements at higher concentrations and isothermal distillation equilifaratian with solutions of known activities in the dilute range. (Reprinted fiom Paul J. Flory, Principles of Polymer Chemistry. Copyright 1953 Cornell University and copyright 1981 Paul J. Flory. Used by permission of the Puhhsher, Cornell University Press.)...

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