Mass Transport in Binary Mixtures and the Diffusion Equation

10 MASS TRANSPORT IN BINARY MIXTURES AND THE DIFFUSION EQUATION 

Subsequent to polymer manufacture, it is often necessary to remove dissolved volatiles, such as solvents, untreated monomer, moisture, and impurities from the product. Moreover, volatiles, water, and other components often need to be removed prior to the shaping step. For the dissolved volatiles to be removed, they must diffuse to some melt-vapor interface. This mass-transport operation, called devolatilization, constitutes an important elementary step in polymer processing, and is discussed in Chapter 8. For a detailed discussion of diffusion, the reader is referred to the many texts available on the subject here we will only present the equation of continuity for a binary system of constant density, where a low concentration of a minor component A diffuses through the major component  

11 MATHEMATICAL MODELING, COMMON BOUNDARY CONDITIONS, COMMON SIMPLIFYING ASSUMPTIONS, 

Engineering design, analysis, control, optimization, trouble shooting, and any other engineering activity related to specific industrial processes, machines, or structures can best be performed using a quantitative study of effect of the parameters as well as of the 

Aris (3) more formally defined a mathematical model thus a system of equations, S, is said to be a model of prototypical system, S, if it is formulated to express the laws of S and its solution is intended to represent some aspect of the behavior of S. Seinfeld and Lapidus (4) gave a more specific definition Mathematical model is taken to mean the formulation of mathematical relationships, which describe the behavior of actual systems such that the dependent and independent variables and parameters of the model are directly related to physical and chemical quantities in the real system.  

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Mass Transport in Binary Mixtures and the Diffusion Equation, 60... 

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