A new route of fabricating porous polyimide membranes

Abstract

A novel experimental route to fabricate porous polyimide membranes (PPMs) with ideal air permeability was reported. The polymer solution layer consisting of the corresponding polyamic acid (PAA), solvent, and dibutyl phthalate (DBP) with a boiling temperature of 340°C was treated by a simple process. The polymer solution layer was first treated at a lower temperature (about 150°C), then the received solid membrane was further imidized at a higher temperature (about 270°C), and finally, DBP was removed from the membrane at a temperature above its boiling temperature. The final asymmetric polyimide membrane with a dense skin layer was obtained. To improve the air permeability of the polyimide membranes, the polymer solution layer was treated between two substrates. And the PPMs with open pores on both sides are fabricated and the air permeability of the films is improved greatly.

Keywords

polyimide / polyamic acid / membrane / additive / porous materials

References

[1] Huang J.G., Cranford R.J., Matsuura T., Roy C. Sorption and transport behavior of water vapor in dense and asymmetric polyimide membranes. J. Membr. Sci., 2004, 241, 187.

[2] Vandezande P., Gevers L.E.M., Vermant J., Martens J.A., Jacobs P.A., Vankelecom I.F.J. solidification of emulsified polymer solutions via phase inversion (SEPPI): a generic way to prepare polymers with controlled porosity. Chem. Mater., 2008, 20, 3457.

[3] Li X., Chen C.X., Li J.D. Formation kinetics of polyethersulfone with cardo membrane via phase inversion. J. Membr. Sci., 2008, 314, 206.

[4] Aslam M., Gregory C., Hatfield J.V. Polyimide membrane for micro-heated gas sensor array. Sens. Actuators B, 2004, 103(1–2): 153.

[5] Pieter V., Li X.F., Gevers L.E.M., Vankelecom I.F.J. High throughput study of phase inversion parameters for polyimide-based SRNF membranes. J. Membr. Sci., 2009, 330, 307.

[6] Kim Y.K., Lee J.M., Park H.B., Lee Y.M. The gas separation properties of carbon molecular sieve membranes derived from polyimides having carboxylic acid groups. J. Membr. Sci., 2004, 235, 139.

[7] Kim Y.K., Park H.B., Lee Y.M. Carbon molecular sieve membranes derived from thermally labile polymer containing blend polymers and their gas separation properties. J. Membr. Sci., 2004, 243, 9.

[8] Woo Y., Oh S.Y., Kang Y.S., Jung B. Synthesis and characterization of sulfonated polyimide membranes for direct methanol fuel cell. J. Membr. Sci., 2003, 220, 31.

[9] Chun K.Y., Jang S.H., Kim H.S., Kim Y.W., Han H.S., Joe Y.L. Effects of solvent on the pore formation in asymmetric 6FDA-4,4′ODA polyimide membrane: terms of thermodynamics, precipitation kinetics, and physical factors. J. Membr. Sci., 2000, 169, 197.

[10] Hiroyoshi K., Kanako N., Hideyuki S., Shoji N. Gas permeation of stability of asymmetric polyimide membrane with thin skin layer: effect of polyimide structure. J. Membr. Sci., 2003, 212, 195.

[11] Sairam S., Loh X.X., Bismarch A., et al. Nanoporous asymmetric polyaniline films for filtration of organic solvents. J. Membr. Sci., 2009, 330, 166.

[12] Wang H.H., Tablet C., Caro J. Oxygen production at low temperature using dense perovskite hollow fiber membranes. J. Membr. Sci., 2008, 322, 214.

[13] Jia Z.Q., Chang Q., Qin J., Hong X.M. Preparation of nanoparticles with a gas-liquid membrane contactor. J. Membr. Sci., 2009, 15, 1.

[14] Jiang L.Y., Chung T.S., Rajagopolan R. Dehydration of alcohols by pervaporation through polyimide Matrimid asymmetric hollow fibers with various modifications. Chem. Eng. Sci., 2008, 63, 204.