Modeling and computation of solvent penetration in glassy polymers

Modeling and computation of solvent penetration in glassy polymers

(Third Party Funds Single)

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Start date: 1. July 2009
End date: 30. July 2011
Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)


The main goal of this proposal is the computational modeling of solvent penetration in glassy polymers. For most engineering applications, Fick s law accurately describes diffusive processes, but one of the applications where it miserably fails is in glassy polymers near the glass transition temperature. In the vicinity of the glass transition temperature, when a low molecular weight solvent diffuses into a glassy polymer, the latter is caused to undergo a rubber-glass phase transition. The diffsive process follows non-Fickian behavior. Whereas the classical Fickian diffusion is referred to as case I diffusion, diffusion in glassy polymers is known as non-Fickian „case II diffusion“. A typical system undergoing case II diffusion is polymethylmethacrylate (PMMA) and methanol, for example.Modeling polymers which undergo case II diffusion is of particular interest in pharmaceutical and automotive industries, for example. Due to the importance of diffusion in many industrial and biological processes, a complete examination from a variety of perspectives and techniques is necessary. One tool at hand is the computational modeling at which this project aims. Hereby, an all-embracing theoretical model is to be set up extending existing approaches. Thus the very challenging modeling of non-Fickian behavior is one main task of this project. The numerical implementation of this ambitious theory is to be done subsequently in order to computationally model distinct typical applications from engineering or biomechanics.