PHASE-BEHAVIOR OF ORDERED POLYMER-SOLUTIONS

Rules for equilibrium phase behaviour, laid down long ago on the basis of the two laws of thermodynamics, appear to be valid also for many polymer systems in which aggregates of various topology occur. The phase rule offers a useful tool for the construction and understanding of phase diagrams for systems in which order of some kind is prevalent in certain ranges in the diagram. 'Double sickle' type phase diagrams, found for surfactant solutions, microemulsions as well as block-copolymer solutions can be traced back to the considerable loss of translational entropy which accompanies aggregation.