Study Of Dissolution And Diffusion Of Gases And Liquids In Polymer

The Solubility and Diffusion Coefficient of gases and liquids in Polymer are very important values in the Industrial Processing. In this work, The vapor-liquid-equilibrium isotherm of the system of methyl ethyl ketone with polystyrene is measured by the method of QCM(Piezoelectric Quartz Crystal Microbalance), at the same time the solvent diffusion curve are acquired. The QCM method needs only 1.5-2 hours and a little reagent, and is regarded as a efficient method.A new model of self-diffusion coefficient is invented by the introduce of a new expression of free volume. Comparing with the existing models, the new model is not only more accurate but also describes the pressure dependence of the solvent self-diffusion coefficients for polymer-solvent systems.The henry's constant of solutes in molten polymer are correlated using the molecular connectivity indices. The calculated results are better than that of which is correlated with the critical properties and acentric factor. The input parameters are connectivity indices which reflect the informations of the structure of molecule, which make the new expression more usefulonce the chemical structure of the substance is known.