Sulfonated copolyimides: influence of structural parameters on gas separation properties

• Published in: Desalination Vol. 145; no. 1; pp. 371 - 374
• Main Authors: Piroux, F., Espuche, E., Mercier, R., Pineri, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 10-09-2002; Elsevier
• Subjects: Applied sciences; Chemical Sciences; CO 2 sorption isotherms; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; Gas permeability; Nonsulfonated diamine; O 2/N 2 selectivity; Polymer industry, paints, wood; Polymers; Sulfonated sequenced copolyimides; Technology of polymers; Gas permeability; Sulfonated sequenced copolyimides; CO 2 sorption isotherms; O 2/N 2 selectivity; Nonsulfonated diamine; Oxygen; Carbon dioxide; Adsorption isotherm; Nitrogen; Experimental study; Sulfonate copolymer; Polyelectrolyte; Sorption; Gas solid adsorption; Selective permeability; Imide copolymer; Property structure relationship; Acid copolymer; CO2 sorption isotherms; sulfonated sequenced copolyimides; O2/N2 selectivity; non-sulfonated diamine; gas permeability
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/S0011-9164(02)00438-1

Structure-properties relationships in terms of gas transport have been established for a large series of sulfonated copolyimides. The permeability and diffusion coefficients of different gases (H
2, O
2, CO
2, N
2) differing by their size and interaction capacity towards the polymers have been determined. CO
2 sorption experiments have also been carried out allowing a direct determination of the solubility coefficients. The analysis of the transport parameters as a function of the copolyimides structure and composition underlines the predominant role of the non-sulfonated sequences and shows that the permeability is mainly governed by the diffusion coefficient. A large range of permeability values can thus be obtained by varying the nature and the content of the non-sulfonated diamine in the copolyimides and for some copolymers, H
2 and CO
2 permeability values are similar. Furthermore, O
2/N
2 selectivity coefficients determined for all the membranes are located near the Robeson curve. As a consequence, some systems, notably those based on (CARDO/ODA) diamines mixture, present a good selectivity/permeability balance.