MONOMOLECULAR FILMS OF COPOLYMERS OF OXYETHYLENE AND OXYPROPYLENE, POLYPROPYLENE GLYCOL AND THEIR BINARY MIXTURES

摘要

The behaviour of monolayers of copolymers of oxyethylene and oxypropylene (UH29 and UH68), polypropylene glycol (UHPPG)and their binary mixtures on air-water interface has been investigated carefully on compression-expansion cycles. The first compression isotherm is approximately an equilibrium one. In the UHPPG-UH29 and UHPPG-UH68 systems, the calculated average π-a curves based on simple additivity of the two individual components coincide with the experimental results reasonably well. It is suggested that the two components are miscible and form near-ideal solution at the air-water interface. The compression-expansion cycle experiments shows some degree of hysteresis. The order of degree of hysteresis for individual components is UH68UH29UHPPG. The explanation for the hysteresis is proposed.