Fabrication of microfiltration membranes from polyisobutylene/polymethylpentene blends

An approach for fabrication of microfiltration membranes by solvent extraction of one of the immiscible components from a polymer blend was developed. Poly(4-methyl-1-pentene) (PMP) was the membrane material, and poly(isobutylene) (PIB) was the extractable component. The PIB content varied in the wide range 0-45 wt%, and all blends could be melted and processed at a temperature of 240 degrees C. A rheological study demonstrated a pronounced non-Newtonian behavior of PMP/PIB blends and their very low viscosity due to interlayer slip. With a PMP content of 55 and 60 wt%, it was possible to fabricate microfiltration membranes with a water permeability of 31 and 3.7 m(3) m(-2) h(-1) bar(-1), respectively. The microfiltration membranes based on both compositions demonstrated good rejection performance at the level of 93%-98% for submicron particles of phthalocyanine dye with a size of 240 nm. These results indicate that the PMP/PIB system can be utilized for fabrication of filtration membranes by means of 3D printing followed by solvent extraction. (c) 2019 Society of Chemical Industry