Abstract

CECOPIERI-GOMEZ, Martha L.  and  PALACIOS, Joaquín. Cálculo teórico y experimental del parámetro termodinámico de interacción de Flory del Poli(adipato de etileno). Rev. Soc. Quím. Méx [online]. 2001, vol.45, n.2, pp.82-88. ISSN 0583-7693.

In this work we present the theoretical and experimetal determinations of the Flory interaction parameter χ, the second virial coefficient A₂, and the solubility parameter δ₂, of Poly (Ethylene Adipate) PEA, a PVC plasticizer. We have used the viscometric method for measuring dilute PEA solutions in good solvents: 1,4 dioxane, benzene, toluene, chloroform, THF and acetone. A procedure based on the Stockmayer-Fixman, (SF), hydrodynamic solution theory allows us to evaluate the thermodynamic parameters via the intrinsic viscosity, [h], measured in several solvents. This method estimates the unperturbed parameter, k_ϑ, in combination with the Mark-Houwink-Sakurada, (MHS), constants, k and a, obtained by viscosity measurements at constant temperature. This procedure is a convenient way, when we want to know the hydrodynamic behavior of the polymers in the unperturbed state, specially when we do not have a theta solvent available, or the theta conditions make unable the viscosity measurements. Our theoretical calculations of the solubility parameter, and interaction parmeter are in good agreement with the experimental values. These results were compared with those reported in the literature for a series of similar adipates, since PEA data have not previously been published.

Keywords : Flory Interaction Parameter; Second virial coefficient; Solubility parameter; Hydrodynamic Properties of Poly(Ethylene Adipate).