New Hybrid Membrane Based on Poly(m-phenylene-iso-phthalamide) for Pervaporation of Methanol/n-Heptane Azeotropic Mixture

The object of this work is a new hybrid membrane based on poly(m-phenylene-iso-phthalamide) (PA) modified with a complex filler consisting of equal amounts of heteroarm star-shaped macromolecules (HSMs) and [BMIM⁺Tf₂N^–] ionic liquid (IL). Comparative studies of the structures have been carried out on samples of membranes made of pristine PA and hybrid PA/HSM and PA/(HSM:IL) containing 5 wt % additives. Methods of AFM, X-ray powder diffraction, measurement of density, and contact angles have been used. The transport properties of membranes have been studied in separation of a methanol/n-heptane mixture by the pervaporation method. The actuality of this problem is associated with the process of oil refining. In pervaporation of an azeotropic methanol/n-heptane mixture, the hybrid PA/(HSM:IL) membrane has demonstrated higher performance and separation factor relative to reference membranes. Mechanical tests of the membranes have revealed a high level of properties important for operation (strength and relative elongation) of the hybrid membrane.