ABSTRACT
At the time the laboratory began investigating hydrophobe-modified polymers, there had developed considerable interest in the spontaneous formation and physical properties of micelles in surfactant solutions. The first polysoap investigated was prepared by quaternizing close to one third of the pyridine groups of poly-2-vinylpyridine with n-dodecyl bromide. Poly-4-vinylpyridine presented a convenient base for studying the transition from normal polyelectrolyte to polysoap by quaternizing part of the pyridine groups with dodecyl bromide and the remainder with ethyl bromide. The surface activities of poly-4-vinylpyridine derivatives, as determined by surface tension and interfacial tension measurements, were very small in the absence of simple electrolyte. In contrast, a bromopropyl-benzene adduct of poly-2-vinylpyridine showed strong surface activity in aqueous solution even in the absence of simple electrolyte. The area between each of these curves and that of the methyl or ethyl copolymer is proportional to the free energy of stabilization for the uncharged compact state relative to the hypothetical uncharged extended state.
