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TURBIDIMETRIC STUDY OF THE DEMIXING PHENOMENON IN LIQUID – LIQUID SYSTEM POLYURETHANE – DIMETHYLFORMAMIDE - WATER


UNGUREANU SIMONA, BÄ‚LÄ‚U LUMINIŢA, CIOBANU CONSTANTIN, POPA MARCEL, APOSTU M. O.*, MELNIG V.*
“GH. ASACHI” UNIVERSITY TECHNIQUE, IAŞI, FACULTY OF INDUSTRIAL CHEMISTRY, B-DUL D. MANGERON, NR. 71A, 6600 - IAŞI, ROMANIA E-MAIL: MIPOPA@CH.TUIAŞI.RO *“AL.I.CUZA” UNIVERSITY, IAŞI, FACULTY OF PHYSICS

Issue:

SCSCC6, Volume IV

Section:

Volume IV (2003)

Abstract:

The present research relates to liquid – liquid demixing phenomena encountered in polyurethane (PU)/N,N’-dimethylformamide (DMF)/water system. The cloud – points were determined by turbidimetric titration for various initial concentrations of PU in DMF. It was experimentally observed that a small amount of water is needed to induce liquid – liquid demixing. The cloud – points were determined by turbidimetric titration for PU/DMF different concentrations between 1÷20 %. The obtained phase diagram is a useful tool for the preparation of membranes with controlled morphology. Morphology and structure of the membranes was studied by Scanning Electronic Microscopy (SEM) technique and by Angular Total Reflection Fourier Transform InfraRred (ATR-FTIR) method. The paper reveals that the morphology of the asymmetric membranes can be anticipated with the help of phase diagram and controlled by casting parameters such as: polymer concentration, coagulation bath composition and temperature.

Keywords:

polyurethane, membranes, turbidimetric titration, SEM, FTIR.

Code [ID]:

CSCC6200304V00S01A0007 [0001378]

Full paper:

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