Preparation of 4-methyl-1-pentene membranes via non-solvent induced phase separation (NIPS)

Poly 4-methyl-1-pentene (PMP) membranes are often used in gas separation and membrane oxygenators in extracorporeal membrane oxygenation (ECMO). Considering the high energy consumption of thermally induced phase separation (TIPS) method, in this article, PMP membranes were prepared via non-solvent induced phase separation (NIPS) under wide preparation conditions. The phase separation behavior of PMP/cyclohexane/ alcohol system, effects of non-solvent additive in casting solution, evaporation temperature (0 degrees C -60 degrees C), evaporation time and coagulation temperature (-10 degrees C -20 degrees C) on the membrane structure and air permeability of PMP membranes were studied. The results showed that, the addition of appropriate amount of non-solvent to the casting solution effectively improved the air permeability. The evaporation step at low temperature led to robust membranes with high air permeability. Extending the evaporation time of the wet membranes increased the mechanical strength and air permeability. The lower coagulation temperature also contributed to a higher air permeability. The prepared PMP membranes showed great promises for applications in membrane oxygenators.