Exploring Torlon/P84 co-polyamide-imide blended hollow fibers and their chemical cross-linking modifications for pervaporation dehydration of isopropanol

Abstract

A research study has been conducted to fabricate and chemically modify Torlon ® 4000T and Torlon/P84 co-polyamide-imide blended hollow fibers as new materials for the dehydration of isopropanol (IPA). It has been found that Torlon/P84 blends are miscible, as confirmed through the single glass transition temperatures (T g s) detected by differential scanning calorimetry (DSC). Both pure and blended hollow fibers fabricated from the dry-jet wet-spinning process do not show sufficient resistance to suppress water and IPA induced swelling, whereas cross-linked pure Torlon hollow fibers show only marginal improvement. However, the Torlon/P84 blended fibers display enhanced separation performance after chemical cross-linking modification with the aid of p-xylenediamine. It is believed that the p-xylenediamine induced cross-linking reactions result in greater chain packing and the reduction of free volume. The highest separation factor obtained was 185 ± 8 for the 85/15 wt.% IPA/H 2 O feed solution and the total permeation flux obtained was 1000 ± 45 g/m 2 h.

Polyamide‐imide nanofiltration hollow fiber membranes with elongation‐induced nano‐pore evolution

“…24 Torlon V R has been used widely in the injection molding of engine parts for racing cars, of molded parts for the space shuttle, and of many other critical components. Only recently has Torlon V R been applied in the membrane field, in areas such as vapor permeation, 25 pervaporation, 24,26,27 and gas separation. [28][29][30] Although Torlon V R has also been utilized to fabricate NF membranes, it has only served as the supporting layer in flat-sheet membranes.…”

Nanometric thin skinned dual‐layer hollow fiber membranes for dehydration of isopropanol

“…Table also compares the current work with literature data on polymeric hollow fiber membranes for IPA dehydration . Since it is not easy to fabricate a hollow fiber membrane with an ultrathin and defect‐free skin layer, and it is difficult to overcome the swelling issue, most polymeric hollow fiber membranes do not possess both high flux and high separation factor simultaneously as shown in Figure .…”

“…Because of importance of IPA recycle, pervaporation dehydration of IPA has been studied by various materials. Tables and tabulate some of literature studies on dehydration of IPA in terms of materials and fabrication techniques, whereas Figure shows a graphical comparison of separation performance among different membranes. As can be observed, inorganic membranes have superior pervaporation performance to polymeric membranes due to their high thermal stability and antiswelling properties.…”

Torlon® hollow fiber membranes for organic solvent reverse osmosis separation of complex aromatic hydrocarbon mixtures

“…In this study, Torlon®, a polyamide‐imide, was chosen as a candidate OSRO membrane material because it has superior mechanical, thermal, and chemical stability . Torlon® has been applied for membrane applications such as vapor permeation, pervaporation, and gas separations . Here, we investigate the applicability of Torlon® to realize OSRO‐type separations of similarly‐sized molecules relevant to the hydrocarbon processing industry.…”