ISSN:
0887-6266
Keywords:
ternary phase diagrams
;
polylactides
;
Flory-Huggins
;
demixing
;
membranes
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Isothermal phase diagrams for the semicrystalline poly-L-lactide (PLLA) and the amorphous poly-DL-lactide (PDLLA) in combination with several solvent-nonsolvent combinations (dioxane/water, dioxane/methanol, chloroform/methanol, and NMP/water) have been determined. The locations of the liquid-liquid miscibility gap, the solid-liquid miscibility gap and the vitrification boundary in the isothermal phase diagrams at 25°C were identified. The liquid-liquid miscibility gap for the systems with PLLA was located in the same composition range as the corresponding systems with PDLLA. For the systems containing PLLA solid-liquid demixing was thermodynamically preferred over liquid-liquid demixing. Attempts were made to correlate the experimental findings with predictions on the basis of the Flory-Huggins theory for ternary solutions using interaction parameters derived from independent experiments. Qualitative agreement was found between the theoretical predictions and the experimentally obtained liquid-liquid miscibility gap. No good agreement was found for the solid-liquid miscibility gap. © 1996 John Wiley & Sons, Inc.
Additional Material:
14 Ill.
Type of Medium:
Electronic Resource
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