Abstract
In this paper thermodynamic properties of poly(methyl methacrylate) (PMMA) in the following polar binary mixtures: 1,2-dichloroethane (DCE)/acetonitrile (ACN), DCE/ethyl acetate (EA), dimethylformamide (DMF)/ACN and DMF/EA have been studied. We have found that the preferential sorption of PMMA in these binary mixtures is very weak and the theoretical equations do not reproduce the experimental values. These differences are explained by taking into account the absence of polymer-solvents or solvent-solvent ternary interaction parameter in the employed equations. Viscometric and light scattering measurements show the existence of a synergistic effect in the four studied systems. This effect is related to the free Gibbs excess energy parameter of the binary mixture. The theoretical values can be found by using a low index coordination number ( z = 3) in the Noel et al. equation. Finally, we have found a relationship between the unperturbed dimensions K θ and the interaction parameter B in the studied systems.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have