Preparation and pervaporation performance of polyimide composite membrane by vapor deposition and polymerization (VDP)
1997; Elsevier BV; Volume: 136; Issue: 1-2 Linguagem: Inglês
10.1016/s0376-7388(97)00163-4
ISSN1873-3123
AutoresH. Yanagisita, Daï Kitamoto, Kenji Haraya, Takashi Nakane, T. Tsuchiya, N. Koura,
Tópico(s)Synthetic Organic Chemistry Methods
ResumoPreparation of polyimide composite membranes by the vapor deposition and polymerization method (VDP) has been investigated. 3,3′,4,4′-Benzophenon tetracarboxylic dianhydride (BTDA), and 4,4′-diaminodiphenyl ether (ODA) were used as monomers. BTDA and ODA were simultaneously deposited on substrates in a vacuum of 10−6 Torr, where the molar ratio of BTDA to ODA is unity. The deposition layer was converted from polyamide acid to polyimide by heating at 200°C for 3 h in an ordinary vacuum oven. The substrates of the composite membranes used were polymide asymmetric membranes. They were prepared by the phase inversion process from the casting solution of 24 wt% of commercial polyimide (PI-2080) and 76 wt% of N,N'-dimethylacetamide. The thickness of the deposited layer formed was ca. 0.05–0.4 μm. Separation performance of polyimide composite membranes were measured by pervaporation method using a 95 vol% aqueous ethanol solution. A composite membrane with a deposition layer thicker than 0.2 μm exhibited a separation factor of 1300.
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