Monolayers of adipate polyesters at air-liquid interfaces

The surface pressure-area isotherms at 24.5 °C are reported for poly (ethylene adipate), poly(trimethylene adipate), and poly (propylene adipate), spread as monolayers at airaqueous interfaces. The monolayers were spread on distilled water and 0.01 N HC1, using benzene, chloroform, and acetone as spreading solvents. Poly (propylene adiptate) was the least compressible of the three, and poly (ethylene adipate) the most. Poly (propylene adipate) did not collapse at the highest pressure's studied. The spreading characteristics of both poly (ethylene adipate) and poly (propylene adipate) were independent of the amount of material used. The spreading of poly (trimethylene adipate) appeared to depend upon the spreading solvent. The effect of structure on the surface pressure—area isotherms and the specific areas for each polymer are discussed.