ACRYLONITRILE-SODIUM METHALLYLSULFONATE COPOLYMER SOLUTIONS - NMR APPROACH TO PHASE-DIAGRAMS AND ORDERING PROCESSES

the physical behavior of solutions of an acrylonitrile-sodium methally lsulfonate copolymer in dimethyl sulfoxide is described from NMR and c alorimetric observations by varying concentration, temperature and the rmal history of the systems. Both the solvent and the polymer can crys tallize in the studied range of temperature. A method is proposed to d etermine the composition of the phases present in solution. At high po lymer concentration, we observe that the physical state of a given sol ution depends on its thermodynamic history and that three distinct pha ses can coexist over a large temperature interval.