Synthetic 6FDA-ODA Copolyimide Membranes for Gas Separation and Pervaporation : Correlation of Separation Properties With Diamine Monomers

Copolyimides were synthesized from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 4-aminophenyl ether (ODA) with 4-aminophenyl sulfone (DDS), 4,4′-methylenedianiline (MDA), 4,4′-bis(3-aminophenoxy)diphenyl sulfone (BADS), 4,4′-bis(3-aminophenoxy) benzophenone (BABP), and 2,6-bis(3-aminophenoxyl) benzonitrile (DABN) as the third monomer. Surface free energies and interfacial free energies were calculated for comparison of the membrane hydrophilicity. Gas permeation was carried out with N2, O2, H2, He, and CO2, and the moiety contributions to membrane selectivity were calculated. DDS and BADS moieties contribute negatively to the selectivities toward O2/N2, H2/N2, and He/N2, and the DABN moiety is favorable for improving CO2/N2 selectivity. Water permeation and dehydration of isopropanol were performed, and the linear moiety contribution method was applied to study the effects of the monomer structures on the temperature and feed concentration dependencies of the permeation flux. The steric effects of DDS and BADS moieties, as well as the interactions of BABP and DABN moieties with water, account for the differences in pervaporation properties of the membranes. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers

[1]  Robert Y. M. Huang,et al.  Synthetic 6FDA-ODA copolyimide membranes for gas separation and pervaporation : Functional groups and separation properties , 2007 .

[2]  Robert Y. M. Huang,et al.  Polymeric membrane pervaporation , 2007 .

[3]  K. Nagai,et al.  Polymer Membranes for Hydrogen Separations , 2006 .

[4]  Jiding Li,et al.  Pervaporation Properties of Polyimide Membranes for Separation of Ethanol + Water Mixtures , 2006 .

[5]  Yun‐Hi Kim,et al.  Synthesis and Characterization of Highly Soluble and Oxygen Permeable New Polyimides Based on Twisted Biphenyl Dianhydride and Spirobifluorene Diamine , 2005 .

[6]  E. Drioli,et al.  Novel PEEK-WC membranes with low plasma protein affinity related to surface free energy parameters , 2004, Journal of materials science. Materials in medicine.

[7]  Tai‐Shung Chung,et al.  Thermal Imidization of the Precursor of a Liquid Crystalline Polyimide , 2002 .

[8]  Pratibha Pandey,et al.  Membranes for gas separation , 2001 .

[9]  P. Luner,et al.  Surface free energy of ethylcellulose films and the influence of plasticizers. , 1999, International journal of pharmaceutics.

[10]  L. Robeson,et al.  A group contribution approach to predict permeability and permselectivity of aromatic polymers , 1997 .

[11]  C. J. Oss,et al.  On the Predominant Electron- Donicity of Polar Solid Surfaces* , 1997 .

[12]  Donald R Paul,et al.  Correlation and prediction of gas permeability in glassy polymer membrane materials via a modified free volume based group contribution method , 1997 .

[13]  R. F. Giese,et al.  The Hydrophilicity and Hydrophobicity of Clay Minerals , 1995 .

[14]  William J. Koros,et al.  Membrane-based gas separation , 1993 .

[15]  S. S. Kim,et al.  Synthesis of crystalline polyimide film by ionized cluster-beam deposition , 1993, Journal of Materials Science.

[16]  Robert Y. M. Huang,et al.  Pervaporation of Water/Ethanol Mixtures by an Aromatic Polyetherimide Membrane , 1992 .

[17]  Jiping Xu,et al.  A Simple Method for Prediction of Gas Permeability of Polymers from Their Molecular Structure , 1991 .

[18]  P. Xu,et al.  Structure of Alkali-Swelling Bacterial Cellulose-Brightener Complex , 1991 .

[19]  Y. Mi,et al.  Structure/permeability relationships of polyimide membranes. Applications to the separation of gas mixtures , 1989 .

[20]  W. Koros,et al.  Relationship between gas separation properties and chemical structure in a series of aromatic polyimides , 1988 .

[21]  M. Salame.  Prediction of gas barrier properties of high polymers , 1986 .