EXAMPLES OF AMPHITROPIC POLYMERS - MONOLAYER FILM, LANGMUIR-BLODGETT-FILM AND LIQUID-CRYSTALLINE PROPERTIES OF SOME POLYMERIC AMPHIPHILES CONTAINING CHOLESTANOL MOIETIES AND THOSE OF SOME CLOSELY-RELATED NON-POLYMERIC AMPHIPHILES

A range of alternating copolymers were prepared by free-radical-initia ted copolymerizations of maleic anhydride with a series of alpha-alken es containing cholestanyl moieties. Derivatives of these copolymers we re prepared by reacting the anhydride residues with methanol, water, d imethylamine and/or morpholine. A related series of non-polymeric amph iphiles containing steroid moieties was also prepared. Isotherms were measured for monolayers of the various polymers and the various non-po lymeric amphiphiles on water and, where possible, Langmuir-Blodgett (L B) multilayers were prepared. The majority of the materials gave good isotherms (relatively steep with collapse pressures >40 mN m(-1)) indi cating that the monolayers were ordered and, as determined by the dete ction of Bragg peaks by X-ray diffraction, Y-type LB films with regula r layer structures. Appropriate materials were also examined, by optic al microscopy and differential scanning calorimetry (DSC), for possibl e liquid-crystalline properties. Four polymers and one non-polymeric a mphiphile exhibited smectic A mesophases. Another non-polymeric amphip hile exhibited a cholesteric mesophase. Thus, examples were found of a mphitropic polymers and non-polymeric amphiphiles which can form organ ised molecular arrangements both because they are amphiphilic and beca use they contain mesogens.