Gas transport in Polymers of Intrinsic Microporosity (PIMs): the case study of amine modification

Polymers, with their high processability and broad range of properties, are the most used material in membrane technology. The need to solve increasingly challenging separation problems, such as CO2 sequestration from flue gas or from biogas requires a continuous research for novel materials with increased separation performance. Polymers are already widely use in industrial gas separation membranes processes and new classes of polymers find spread interest as promising materials for the future. Recently, Polymer of Intrinsic Microporosity (PIMs) have received increasing attention by membrane researchers. They are glassy polymers with very rigid and contorted macromolecular backbones, which provide them high free volume, and hence high permeability [1]. Typically, PIMs comprise fused ring sequences interrupted by spiro-centres, such as the archetypal membrane-forming PIM-1, which attracted attention as a membrane material when it was found to surpass the state-of-the-art limits for polymeric gas membrane separation and now defines the current limits of the membrane gas separation technology for several gas pairs. Since the introduction of the archetypal PIM-1, more than a decade ago [2], several different modification were proposed to develop PIMs with improved permselectivity properties, such as changes in the PIMs structure [3] or the introduction of functional groups [4]. Recently, amine groups were added to the PIM-1 structure in order to enhance the affinity between the membrane and CO2 [5]. The aim of this work is to discuss the gas transport properties of a series of PIMs modified with different amine contents, with particular focus on sorption and diffusion coefficients in these polymer membranes. Keywords: gas separation; membrane technology; Polymers of Intrinsic Microporosity; chemical modification; References [1] N. B. McKeown, P. B. Budd, Macromolecules, 43, 5163 (2010). [2] P. B. Budd, E. S. Elabas, B. S. Ghanem, S. Makhseed, N. B. McKeown, K. J. Msayib, C. E. Tattershall, D. Wang, Adv. Mater. 16, 456 (2004) [3] M. Carta, R. Malpass-Evans, M. Croad, Y. Rogan, J. C. Jansen, P. Bernardo, F. Bazzarelli, N. B. McKeown, Science, 339, 303 (2013) [4] N. Du, G. P. Robertson, J. Song, I. Pinnau, M. D. Guiver, Macromolecules, 42, 6038 (2009) [5] C. R. Mason, L. Maynard-Atem, K. W. J. Heard, B. Satilmis, P. M. Budd, K. Friess, M. Lanc?, P. Bernardo, G. Clarizia, J. C. Jansen, Macromolecules, 47, 1021 (2014)