Monolayers of Linear Saturated Succinate Polyesters at Air-Liquid Interfaces

The surface pressure-area isotherms at 25 °C are reported for some linear saturated polyesters spread as monolayers at air-aqueous interfaces. Monolayers of poly (ethylene succinate), poly (pentamethylene succinate), and poly (neopentyl succinate) were studied on distilled water and 0.01 N hydrochloric acid subphases. Poly (ethylene succinate) monolayers are in the expanded state and collapse at low surface pressures. Poly (pentamethylene succinate) monolayers are also expanded, but show no definite collapse, even at the highest surface pressures studied. Monolayers of poly (neopentyl succinate) collapse at high surface pressures, and are less expanded, over the entire surface pressure range studied, than the monolayers of the other polymers studied. The specific area for each polymer and the effect of structure on the surface pressure-area isotherms of poly (pentamethylene succinate) and poly (neopentyl succinate) are discussed.