Abstract
The chemical stability of polymer membranes, i.e., their ability to preserve the size, shape, and pore structure in contact with aggressive organic solvents, largely determines their separation characteristics in filtration of organic media. Methods for enhancing the stability of porous membranes based on commercial polymers (polysulfone, polyphenylsulfone, polyacrylonitrile) by chemical and/or physical modification are considered. Chemical modification consists in covalent cross-linking of matrix polymer chains; in some cases, cross-linking of macromolecules requires their preliminary functionalization. Physical modification involves blending of a matrix polymer with another polymer. A promising way to stabilize various membranes is combining a matrix polymer with a chemically cross-linked additional polymer, i.e., forming a semi-interpenetrating network.