Poly(ethylene-co-vinyl alcohol) (EVOH 32) / 1,3-propanediol mixtures are processed by thermally induced phase separation for the formation of porous membranes. The crystallization line was determined both by the cloud-point and DSC methods. Two precursor solution compositions, four quench temperatures and various aging times were explored. It is found possible to generate both polymer-crystallization controlled morphologies (for high quenches and/or sufficiently aged dopes), especially globular microporous ones, and novel nano-scale porous morphologies dominated by intra-binodal phase separation (for low quenches and limited or no precursor solution aging). Structural characterization of the membranes was accomplished via application of scanning electron microscopy and wide angle X-ray diffraction.
Journal of Applied Polymer Science 131(12), 40374(8pages)