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Preparation of polyimide composite membrane by chemical vapor deposition and polymerization technique (CVDP)
Author(s) -
Yanagishita H.,
Nakane T.,
Nozoye H.,
Yoshitome H.
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070490402
Subject(s) - polyimide , pyromellitic dianhydride , membrane , pervaporation , polymerization , interfacial polymerization , materials science , composite number , chemical engineering , polymer chemistry , phase inversion , chemical vapor deposition , thin film composite membrane , solubility , solvent , layer (electronics) , chemistry , composite material , organic chemistry , polymer , monomer , permeation , nanotechnology , reverse osmosis , biochemistry , engineering
A dry process of chemical vapor deposition and polymerization (CVDP) was employed to prepare a polyimide composite membrane for water–ethanol separation, using an apparatus newly developed for this investigation. The characteristics of the apparatus were studied by depositing pyromellitic dianhydride (PMDA) and 4,4′‐diaminodiphenyl ether (P,P′‐oxydianiline, ODA) in a vacuum of 10 −6 Torr. Deposited layers were converted to a thin polyimide film by heating at 200°C for 3 h in a vacuum. The composite membranes were prepared by forming a polyimide layer of 0.2 μm thickness on the surface of asymmetric supporting membranes made by the phase‐inversion process. The polyimide composite membranes prepared under the best conditions exhibited a separation factor α (H 2 O/EtOH) of over 140 for 95 vol% aqueous ethanol solution with flux of 0.1 kg/m 2 h at 25°C in pervaporation mode. Also, it was demonstrated that this new technique of chemical vapor deposition and polymerization (CVDP) was very useful for the preparation of a solvent‐resistant composite membrane in a completely dry process. © 1993 John Wiley & Sons, Inc.