Handbook of Solvents - George Wypych - ChemTech - Ventech!

5.4 Mixed solvents - polymer solubility 275
Table 5.4.4. Parameter values giving the minimum deviation (δ) between theory and
experiment, for the preferential adsorption coefficient, λ, calculated according to the
Association Equilibria Theory. Reprinted with permission from Horta et al. 106
(Copyright (1989) American Chemical Society)
Polymer σ gBA’ ηa σc
gAC’-r
rAgBC’
ηc δ
1 PMMA 400 0.85 244 400 0.0 5.7 0.034
2 PEMA 400 0.85 244 400 -1.2 59.3 0.028
3 PiBMA 400 0.85 244 400 -2.3 129.5 0.018
4 PMMA 400 0.30 100 400 -3.4 243.2 0.013
5 PEMA 400 0.30 100 400 -2.75 169.2 0.014
6 PiBMA 400 0.30 100 400 -1.6 188.2 0.009
7 PMMA 400 0.85 244 375 -0.1 11.2 0.034
8 PEMA 400 0.85 244 375 -2.2 145.4 0.028
9 PiBMA 400 0.85 244 375 -1.6 100.7 0.035
10 PMMA 400 0.30 100 375 -2.45 195.5 0.013
11 PEMA 400 0.30 100 375 -1.75 125.0 0.016
12 PiBMA 400 0.30 100 375 -0.5 45.6 0.016
The results obtained are a good description of the experimental data on these ternary
systems. Effectively, the shape of the variation of λ with solvent composition was well reproduced
by the association equilibria theory, as it is shown in Figure 5.4.2.
It has extended the same theoretical treatment to other closely related systems, a family
of poly(dialkyl itaconates). 107 Preferential adsorption coefficient λ was determined and
calculated according to the association equilibria theory, and using classical thermodynamic
theories. 108,103,104,105
The dependence of the preferential adsorption coefficient for poly(dimethyl itaconate)
(PDMI), poly(diethyl itaconate) (PDEI), poly(dipropyl itaconate) (PDPI) and poly(dibutyl
itaconate) (PDBI), in 1,4-dioxane/methanol mixtures, as a function of the methanol composition
(u BO) is shown in Figure 5.4.3. The results are very similar to those of poly(alkyl
methacrylates) in the same solvent. 106
Comparison between theory and experimental for λ, by using classical thermodynamic
theories 103-105,108 are shown in Figure 5.4.4.
The results obtained are a good description of the experimental data on these ternary
systems. Effectively, the shape of the variation of λ with solvent composition was well reproduced
by the association equilibria theory. It can be concluded that the association equilibria
theory of preferential adsorption in systems with solvent-solvent and solvent-polymer
interactions describe in a quantitative way the experimental results of λ. Although, the systems
in which the theory has been applied are closely related. More recently, there was no
other systems studied to apply this theory.