MONOLAYERS OF AMYLOSE ESTER DERIVATIVES

Amphiphilic polymers of amylose tri(n-decanoate) (C10AS) and amylose tri(n-octadecanoate) (C18AS) were prepared and examined with respect to their ability to form monolayers at the air-water interface. The surface pressure-area isotherm of C10AS was found to have a plateau region, indicating a monolayer-to-bilayer transition, while the isotherm for C18AS had no such plateau. Transmission electron microscopic observations of the transferred films revealed that C10AS formed a homogeneous monolayer film at a particular point of the pi-A isotherm, while C18AS gave no homogeneous film at any point of the isotherm. These results are different from those derived from the corresponding cellulose esters. The differences in the isotherms and fine structures of the transferred films are discussed in terms of the difference in chemical structure between amylose and cellulose.