SURFACTANT-INDUCED MESOMORPHIC BEHAVIOR OF FLEXIBLE POLYMERS

Conditions for micro phase separated structures based on flexible poly mers associated with surfactants have been investigated. Reasonably st rong attractive interactions are required to oppose macro phase separa tion between polymer and surfactant. In order to obtain micro phase se paration, additionally a sufficiently strong polar-nonpolar repulsion has to be present. Poly(4-vinyl pyridine), poly(2-vinyl pyridine) and polyamide 6 have been used as model polymers in this work. Association s based on protonation, metal coordination and hydrogen bonding are pr esented and shown to yield micro phase separation under suitable condi tions. In the charged systems, the polar-nonpolar repulsion easily bec omes large enough to render micro phase separated structures. In hydro gen bonded (i.e. noncharged) systems a more delicate balance can be ac hieved in which case an order-disorder transition takes place from a h omogeneous state, exhibiting nonetheless a distinct SAXS peak due to c haracteristic block copolymer-like fluctuations, to a micro phase sepa rated ordered state.