Prospects of co‐poly(biquinoline‐hydrazide‐imide)s for separation of benzene‐isopropanol mixture via pervaporation

Abstract

Poly(biquinoline dicarbohydrazide)-co-(bistrimelliteimide) methylene-bisanthranylide (PQHI) and its metal-polymer complex PQHI-Cu + containing several types of functional groups (hydrazide, carboxyl, amide, and imide fragments) were synthesized. Dense thin-film membranes were prepared to study transport properties of these polymers in the separation of a benzene and isopropanol (IPA) mixture via pervaporation. Comprehensive studies of structure, physical and mechanical properties of the novel membranes were carried out. Structure of the polymer films was characterized using scanning electron microscopy. Measurements of physical and mechanical properties showed good performance capabilities of polymers as membrane materials. Transport properties of the synthesized polymers in pervaporation of benzene-IPA mixtures were characterized by determination of total flux, separation factor, as well as permeability and selectivity of the films. It was experimentally found and confirmed by quantum chemical calculations that the novel PQHI-based membranes are benzene selective due to the presence of functional groups capable of H-bonding. The benzene/IPA separation factor is equal to 38 for the PQHI membrane in pervaporation of the mixture containing 20 wt% of benzene.

Novel Design of Co-Poly(Hydrazide Imide) and Its Complex with Cu(I) for Membrane Separation of Methanol/Dimethyl Carbonate Mixture

“…Novel bifunctional monomer 2,2′-biquinoline-6,6′-dicarbohydrazide ( Figure 1 ) was synthesized according to the procedure described in [ 42 ]. The structure of the synthesized monomer was confirmed using 1H NMR spectroscopy.1H NMR (DMSO-d6) d (ppm) 4.45 (s, 4H), 8.88 (d, 2H), 8.79 (d, 2H), 8.70 (d, 2H), 8.29 (d, 2H), 8.25 (s, 2H), 10.10 (s, 2H).…”

“…N,N’-diphenyloxide-bistrimelliteimide acid dichloride was synthesized according to the procedure described in [ 42 ]. Synthesis of poly(2,2′-biquinoline-6,6′-dicarbohydrazide)-co-(bistrimelliteimide) methylene-bisanthranylide (PHI) was carried out using methylene-bisanthranilic acid and 2,2′-biquinoline-6,6′-dicarbohydrazide in a ratio of 80:20 (mol.%) as well as N,N’-diphenyloxide-bistrimelliteimide acid dichloride by low-temperature polycondensation ( Figure 2 ).…”

“…A representative of the poly(biquinoline dicarbohydrazide)-co-(bistrimelliteimide) has been considered promising for studying it as a membrane polymer [ 41 ]. In our previous work, the similar polymer {poly(2,2′-biquinoline-4,4/-dicarbohydrazide)-co-(bistrimelliteimide) methylene-bisanthranylide} was synthesized, which proved to be effective in the separation of the benzene/isopropanol mixture by pervaporation [ 42 ].…”

“…Another approach to changing the flexibility of a polymer chain is to introduce aromatic fragments into the polymer chain, in which the arrangement of substituents increases or decreases the number of possible conformations and changes the flexibility of the chain. We have previously used this approach in the synthesis of polymers containing 2,2’-biquinoline fragments, which provided free rotation around a single bond connecting two quinoline rings [ 42 ]. The polymer chains containing 2,2’-biquinoline fragments, in which functional substituents are located in the positions 4,4′, acquired the ability to form new conformations, i.e., to have kinetic flexibility.…”

Copolyimide molecular brushes with poly(methacrylic acid) side chains as additive to polyphthalamide membrane: Organization, physical, and transport properties

“…[22][23][24][25] Membrane pervaporation is a very promising technique for the separation of complex mixtures of liquid components, including close-boiling and azeotropic mixtures. [26][27][28] The use of pervaporation to separate mixtures of methanol (MeOH) and methyl tert-butyl ether (MTBE) (polar and nonpolar compounds) is caused by the fact that these components form an azeotropic mixture of 14.3 wt% methanol and 85.7 wt% MTBE at 20 С and 760 mmHg. 29 MTBE is a high-octane component used as a gasoline additive and antiknock agent.…”