Poly(urethane-imides) and Poly(ester-imides) as Promising Materials for Gas Separation and Pervaporation Membranes

This review focuses on the separation properties of membranes based on poly(urethane-imides)—modern products of the chemical modification of polyimides and polyurethanes. The membrane properties of poly(urethane-imides) are reviewed in terms of their chemical design. Membranes based on multiblock (segmented) polymers, polyimides crosslinked by polyurethanes, hybrid poly(urethane-imide) materials, and poly(urethane-imides) subjected to the selective destruction of urethane blocks are considered. The main directions of synthesis of membrane poly(urethane-imides) are described, and reactants and reaction conditions are presented. The transport and separation properties of poly(urethane-imide) membranes in separation, pervaporation, and ultrafiltration processes are addressed in detail. Applications of poly(urethane-imide) membranes are discussed. The review provides insight into the importance of poly(urethane-imide) gas separation and pervaporation membranes for separation processes.