Flory-Huggins theory, melting point depression

Application of the Flory-Huggins theory to the melting point depression gives the relationship1... 

Using Flory-Huggins theory it is possible to account for the equilibrium thermodynamic properties of polymer solutions, particularly the fact that polymer solutions show major deviations from ideal solution behavior, as for example, the vapor pressure of solvent above a polymer solution invariably is very much lower than predicted from Raoult s law. The theory also accounts for the phase separation and fractionation behavior of polymer solutions, melting point depressions in crystalline polymers, and swelling of polymer networks. However, the theory is only able to predict general trends and fails to achieve precise agreement with experimental data. 

According to the Flory-Huggins theory, the equilibrium melting point depression can be related to the polymer-polymer interaction parameter, Xi2> by (46,47) ... 

Equation (9.9), however, only approximately describes the internal dilution of a liquid crystalline copolymer [64]. Here internal means that the diluent is part of the chain and not a second independent component. Nishi and Wang [67] have derived equation (9.10) which describes polymers diluted by polymers. Their extension of the Flory-Huggins-Staverman theory gives the melting point depression ... 

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