TITLE:
Surface Tension and Foam Stability Prediction of Polydimethylsiloxane-Polyol Systems
AUTHORS:
Oscar Arciniega Saavedra, Jesús Gracia Fadrique
KEYWORDS:
Gibbs Elasticity Modulus; Foamability; Langmuir Isotherm; Gibbs Adsorption Equation
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.2 No.4,
November
26,
2012
ABSTRACT: The Gibbs elasticity modulus represents an important tool to predict the foamability for transient and permanent foams like polyurethane flexible systems. Elasticity is related to foamability and so is used as a synonymous for the purpose of this paper. In this article we propose a method and a thermodynamic model to analyze the espumability of silicone surfactants in polyol binary mixtures using surface tension data. The present work describes foamability through the Gibbs elasticity modulus expressed in terms of first and second derivatives of surface pressure vs bulk composition. Furthermore, the Gibbs adsorption equation and the corresponding novel surface equation of state based on a modification of the Langmuir isotherm resulted in an elasticity equation with analytical solution. It is shown that according to foam model systems of surfactant solution in polyol used at commercial processes, optimum concentration level of surfactant obtained at this article by Gibbs adsorption equation and maximus on elasticity modulus finally match.