THERMALLY-INDUCED PHASE-SEPARATION IN TERNARY CRYSTALLIZABLE POLYMER-SOLUTIONS

Microporous membranes were prepared by the thermally induced phase sep aration (TIPS) process of a ternary solution of HDPE, ditrydecylphthal ate and hexadecane. The equilibrium phase diagram calculations were ca rried out in terms of a pseudo-binary system, considering the solvent mixture to be one component, to show the effect of the interaction par ameter on the phase diagram. The experimental results showed that by v arying the composition of the solvent pair, i.e., by varying the inter action parameter systematically, the phase diagrams can be controlled successfully. Liquid-liquid phase separation was obtained also below t he melting point by controlling the composition of the solvent mixture . It is also shown that the membrane morphology can be controlled with different solvent compositions when the cooling conditions are kept c onstant.