ating fluid theory (SAFT) is found to be in excellent agreement with the simulation
results for the thermodynamic properties of hard-chain fluids. The ‘attractive’ inter-
actions can be added as a perturbation to the reference hard-chain term, to mimic
real polymer systems. Different variants of SAFT have developed based on the way
these ‘attractions’ are added. A brief review of the different versions of SAFT can be
found in chapter 2, along with their strengths and shortcomings. One common short-
coming is that neither of them is able to provide an accurate description of the phase
behavior of polymer solutions over the whole range of polymer weight fractions [48].
Hence, one of the specific objectives of this research is the development
of an improved EOS based on SAFT for polymer systems, which can accu-
rately predict the phase behavior of polymer solutions over range of polymer weight
fractions.
Discussion of SAFT based EOS is incomplete without a description of TPTl,
which is at the heart of this work and other variants of SAFT. Hence, section 2 of
this chapter gives a brief description of TPTl.
1.1.2 Molecular modeling of the microstructure and thermo-
dynamics of inhomogeneous polymers
As mentioned in the previous section, polymers are often immiscible. When two
polymers A and B are mixed together, the different chemical nature of the two poly-
mers and low entropy of mixing causes them to separate into А-rich and В-rich do-
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