Flory-Huggins Solution Theory—and Beyond

Paul J. Flory, Nobel laureate and a pioneer in the field of polymer chemistry, wrote  

1911 Solution-grafted block copolymer of styrene butadiene 

Krause [5] reviewed the miscible polymer pairs reported in the literature. She found that there were 282 chemically dissimilar polymer pairs that appeared to be miscible in the amorphous state at room temperature. She found that 15% of these were miscible on account of specific interactions such as hydrogen bonding 15% of the miscible pairs were due to clever choice of copolymer composition. The compositional window over which copolymers are miscible with each other can be calculated from the Flory-Huggins theory. 

The free energy, G, of a system is the amount of energy that can be converted to work at constant temperature and pressure. It is named after the thermodynamic-ist Gibbs. Helmholtz free energy, H, of a system, is the amount of energy that can be converted to work at constant temperature. Enthalpy was first introduced by Clapeyron and Clausius in 1827 and represented the useful work done by a system. Entropy of a system, S, represents the unavailability of the system energy to do work. 

It is a measure of randomness of the molecules in the system, and is central to the quantitative description of the second law of thermodynamics. Internal energy, U, is the sum of the kinetic energy, potential energy, and vibrational energy of all the molecules in the system. 

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