Structure and Gas Transport Properties of Polybenzoxazinoneimides with Biquinoline Units in the Backbone

Abstract

Summary: Four polymers with heteroaromatic structures were synthesized starting from dichloroanhydride of 2,2 / -biquinoline-7,7 / -dicarboxylic acid. These are imidecontaining polyamic acid and product of its cyclization polybenzoxazinoneimide as well as complexes of these two polymers with Cu(I). Dense film membranes prepared from the four polymers were characterized in terms of their density and free volume. The gas permeabilities to H 2 , O 2 , N 2 , CO 2 , and CH 4 of the four films and the selectivities in separations of industrially important gas pairs were determined. Polymer chemical structures, polymer free volumes, diffusion coefficients and the sizes of gas molecules were correlated with polymer permeabilities. The prepared and investigated polymers show very good separation properties located near the upper bound lines in Robeson's diagrams.

Synthesis and Crosslinking of Polyether-Based Main Chain Benzoxazine Polymers and Their Gas Separation Performance

“…CO 2 was highly soluble in PEG due to the quadrupole moment resulting in favourable intermolecular interactions with polar (ether) groups in polymers, where the diffusion of CO 2 and other gases was relatively high and did not influence the selectivity because of the PEGs’ rubbery nature, leading to enhanced gas permeability and solubility selectivity [ 4 , 5 , 6 ]. In addition, hetero-aromatic polymers like polyimides and polyamides show specific physicochemical properties, such as a high value of gas pair selectivity (e.g., CO 2 /N 2 or CO 2 /CH 4 ) in gas separation, which make them promising materials for membrane technology applications [ 7 , 8 , 9 ]. Likely, oxazine, which is also a member of N-containing organic heterocyclic, is a favourable structure in a polymer membrane for CO 2 separation.…”

Improved Hydrogen Separation Using Hybrid Membrane Composed of Nanodiamonds and P84 Copolyimide

“…The search for new membrane materials with improved transport properties is one of the priority scientific tasks. Among various membrane polymers, aromatic polyimides and their derivatives are of undoubted interest due to their unique gas separation properties, which are combined with high chemical and thermal stability [10,11,12]. The problem of the hydrogen separation from CO 2 and CH 4 has been studied using membranes based on aromatic polyimides [13,14], their mixtures with polymers of another nature [15], and the products of polyimide chemical modification with cross-linking agents [16,17,18,19,20].…”

Novel Polyester Amide Membranes Containing Biquinoline Units and Complex with Cu(I): Synthesis, Characterization, and Approbation for n-Heptane Isolation from Organic Mixtures

“…Metal-polymer complexes can be obtained on the basis of heteroaromatic polymers whose backbone was functionalized by units containing biquinoline groups capable of forming coordination bonds with transition metals, particularly copper(I) salts. The chemical structure of such metal-polymer complexes can be defined as pseudo-crosslinked systems with high-strength deformation properties and significant thermal stability, which determine their operational characteristics [7][8][9].…”