INTERACTIONS BETWEEN POLY(DIALLYLDIMETHYLAMMONIUM CHLORIDE) AND POLY(ACRYLIC ACID) IN DEPENDENCE ON POLYMER CONCENTRATION

The phase diagram of ternary system, i.e. poly(diallyldimethylammonium chloride), poly(acrylic acid, sodium salt), and water was investigate d by varying the molecular weight of the components. In general, a ran ge of phase separation is surrounded by a one-phase system. The range of phase separation can be subdivided into a region of flocculation an d/or co-acervation in contrast to stable symplex dispersions. By incre asing the molecular weight of the components the range of phase separa tion is increased and phenomena of flocculation followed by coacervati on were observed predominantly. Above a molecular weight of 10 000 g/m ol the transition to concentrated macroscopic homogeneous one-phase sy stems was observed at a constant ionic strength of 2 mol/l coinciding with the critical ionic strength for Coulombic interactions in this sy stem. That means the transition to concentrated one-phase systems can be understood by the disappearance of Coulombic forces above a system- specific ionic strength resulting in a quite additive behaviour of the mixtures with regard to the components.