Polymers in Binary Solvents. Cosolvency Effect Preferential Adsorption Phenomena

5 Polymers in Binary Solvents. Cosolvency Effect Preferential Adsorption Phenomena 

Most of the studies on polymers such as polyamides in solution are limited because the insolubility of these polymers in common solvents. This fact makes their characterization very difficult [87] The degree of order or crystallinity shown by these polymers caused by intra- and inter- chain interactions affect their solubility and their general properties. 

In order to illustrate this problem, it is interesting to analize the unsubstituted polyamides prepared from aliphatic diamines and aromatic diacids or from aliphatic diamines and aliphatic diacids. They are only soluble in solvents such as sulphuric acid, trifluoracetic acid, m-cresol, etc. 

The intrinsic viscosity [r ] for these polymers was chosen as indicative of the thermodynamical power of the binary solvent. 

The intrinsic viscosities of POT and POS in the different solvent/non- solvent mixture are higher than the corresponding intrinsic viscosities in the pure solvent. These positive deviations of [tt ] relative to the solvent m - cresol suggest that the m -cresol/cyclohexane mixture has a GE O [90], 

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