Dissolution mechanism of glassy polymers

Experimental studies involved measurement of the various moving fronts in the polymer-solvent system. In addition, mathematical models were developed to understand the dissolution mechanism of both rubbery as well as glassy polymers and the model predictions were compared to the experimental results. 

The reptation idea could account for the effect of polymer molecular weight and solvent concentration on the dissolution rate. However the key concentration identified in this approach [57,59] is one at the surface. This implies independence of the solvent concentration history. This may not be true as the disentanglement of polymer chains does not commence till the local solvent concentration is greater than a critical value at which the local glass transition temperature is lowered below the experimental temperature so that the glassy polymer changes into a gel. Also, all of the efforts discussed so far failed to take into account the effect of the viscoelastic properties of the polymer on the dissolution mechanism. 

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