Heterogeneous ion exchange membranes based on thermoplastic polyurethane (TPU): effect of PSS/DVB resin on morphology and electrodialysis. Issue 6 (16th January 2020)

• Record Type: Journal Article
• Authors: Ahmad, Muhammad; Qaiser, Asif Ali; Huda, Noor Ul; Saeed, Anem
• Is Part Of: RSC advances. Volume 10:Issue 6(2020)
• Page Start: 3029
• Page End: 3039
• Publication Date: 2020-01-16
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9ra06178a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Membrane morphology and electrochemical properties depend on PSS/DVB resin content and swelling in addition to interaction with TPU. Abstract : In this research, novel heterogeneous cation exchange membranes based on thermoplastic polyurethane (TPU) have been prepared by the solution casting technique. The effects of incorporation level of sulfonated polystyrene divinyl-benzene (PSS/DVB) resin on water uptake, ion exchange capacity, membrane potential and salt extraction have been elucidated. Morphological and water uptake studies suggested a two-phase heterogeneous membrane morphology owing to the presence of hard and soft segments in the TPU backbone and swelling of PSS/DVB particles. This morphology was shifted to a semi-gelled morphology throughout the membrane bulk when resin loading exceeded 50 wt%. The physically cross-linked hard segments in the TPU backbone ensured a compact membrane morphology and prevented the formation of water channels. The membrane potential showed that increasing the resin content increased the membrane transport number (max. 0.95) up to 50 wt% resin loading and beyond this, the transport number started decreasing showing a pronounced effect of voids and water flow channels developing on excessive swelling. The permselectivity reached a maximum (up to 0.92) and salt extraction values also increased (by varying voltage) up to 50 wt% loading and started decreasing beyond this optimum content. This study shows successful development of low-cost heterogeneous cation exchange membranes based on TPU with acceptable electrochemical properties.