Microporous membrane formation via thermally-induced phase separation. II. Liquid—liquid phase separation

Microporous membranes have been prepared via thermally-induced liquid—liquid phase separation of isotactic polypropylene—n,n bis (2-hydroxyethyl) tallowamine mixtures. The thermally-induced phase separation process is discussed in terms of the thermodynamics of the binary mixture and possible phase separation mechanisms. It is demonstrated that membranes can be produced by liquid—liquid phase separation followed by solidification of the polymer or by solid—liquid phase separation.