Interaction of polyamides with solvents. I. A preliminary survey of the swelling of crosslinked nylon 66 in various types of solvents

The swelling in various liquids of discs of nylon 66, crosslinked by the radiation from an atomic pile, has been interpreted using the Flory‐Rehner treatment of the swelling of cross‐linked networks. Values of χ 1 , the polymer‐solvent interaction parameter, found in this way have been discussed in terms of the physical properties of the liquids. The solvent power of about twenty phenols can be correlated with their known ability to form hydrogen bonds. Intramolecular bonding, as in guaiacol or o ‐chlorophenol, reduces the solvent power. Partially hindered phenols, i.e. , those with one bulky hydrocarbon group ortho to the hydroxyl, show high solvent power, probably because polymer‐solvent interaction is not hindered sterically as much as solvent‐solvent interaction. Other classes of solvents, e.g. , inorganic and organic acids, inorganic salts in hydroxylic solvents, are also discussed briefly. Some implications of these results in such technological fields as plasticizers and dyeing assistants are suggested.