The Painter-Coleman Association Model PCAM

The first two terms represent the combinational entropy of mixing. Since these entropy terms are usually small in polymer blends, AG, is dominated by the balance between the third and fourth terms. The third term represents physical forces that can be estimated using Hildebrand s approach from solubility parameters calculated using group contribution methods for a set of carefully chosen groups which are free from association (see also Section 2.1.6) [8,15]. The fourth term represents the favorable hydrogen-bonding contribution to AG - Its 

Coleman et al. uses Fourier transform infrared (ETIR) spectroscopy to obtain the association constants, K, for all of the hydrogen-bonding equilibria occurring in the pure polymers, and in the blends. Using a van t Hoff-type plot, the enthalpies of hydrogen bonding can be calculated. 

Analysis of the Miscibility Using Molecular Modeling Calculations 

by building modeling cells for the pure polymers and for the mixture, and by calculating the CEDs for each of those cells, the internal energy of mixing per unit volume of mixture, A , /V can be obtained. Using also Eqs (2.20) and (2.13) and recalling that AH AE, the interaction parameter can be obtained from  

As discussed, miscibility is a rare phenomenon in polymers. However, miscibility conditions can be satisfied in the following cases. 

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Theoretical miscibility windows for (a) VDAT-PS/T-PBMA and (b) A-PS/T-PBMA blends obtained from the Painter-Coleman association model PCAM ( ) spinodal curve and experimental data ( ) two-phase system (o) one-phase system. (Reprinted with permission from Kuo, S. W., and Hsu, C. H. 2010. Miscibility enhancement of supramolecular polymer blends through complementary multiple hydrogen bonding interactions. Polymer International 59 998-1005. Copyright 2010, Wiley-VCH, Germany.)... 

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