Aromatic copolyimide membranes for high temperature gas separations: H₂/CH₄, H₂/N₂, and O₂/N₂

Abstract

SynopsisA series of high-molecular weight condensation polyimides prepared from pyromellitic dianhydride ( PMDA) or 3,3,4,4'-benzophenone tetracarhoxylic dianhydride (BTDA) with 4,4'-oxydianiline (ODA) and/or 1,5-diaminonaphthalene (NA), and a series of high-molecular weight condensation poly (amide-imides) prepared from trimellitic anhydride acid chloride (TMAC ) with ODA and/or NA were evaluated to determine, in the temperature region 50-250°C, the effect of polymer molecular structure on the permeability and ideal permselectivity of hydrogen, oxygen, nitrogen, and methane. Replacement of ODA with NA generally decreases the permeability of each gas but it increases the permselectivity, which is explained by suppression of both the packing disruption effect and intrasegmental mobility of the amine segments. In general, the overall lower permeation values for the TMAC series of polyimides are much lower than the BTDA-derived series, being the highest for the PMDA-derived series. Permeation data were used to calculate the performance of a hollow fiber module on an industrial scale. It is shown that hydrogen can he efficiently recovered (> 90% ) with a purity of at least 95% from ammonia synthesis off-gas with a feed concentration of 61 mol % of hydrogen.

Simultaneous Improvement of Permeance and Permselectivity of 3,3',4,4'-Biphenyltetracarboxylic Dianhydride-4,4'-Oxydianiline Polyimide Membrane by Carbonization

“…Effect of Chemical Structure of Polyimides on Gas Permeability and Selectivity. Organic glassy polymers like polyimides are very promising as materials for membranes as they have excellent permselectivity and stability (Chem et al, 1984;Sykes and Clair, 1986;O'Brien et al, 1987O'Brien et al, ,1988Kim et al, 1988;Stem et al, 1989; Okamoto et al, 1989;Tanaka et al, 1989aTanaka et al, ,b, 1992a,b; Coleman and Koros, 1990; Buys et al, 1990; Kneifel and Peinemann, 1992). In the last decade, many efforts have been made to understand the relationship between the chemical structure of polyimide and its gas permeation behavior.…”

Derivatives of 4, 4’‐Oxydianiline Show Distinct In Vitro Cytotoxicity, Apoptosis Induction, and Selectivity against HepG2 Cancer Cells

“…4,4’‐ oxydianiline commonly abbreviated as ODA has been efficaciously used since a long time in the field of material chemistry for development of promising materials for membranes owing to their properties of excellent permselectivity and stability in the form of organic glassy polymers like polyimides . The derivatives of ODA displayed excellent thermal stability and increased membrane permeability due to the introduction of a rigid and bulky dianiline structure with inhibited rotation around −O− linkages.…”

Synthesis and gas transport properties of random amide imide copolymers

“…The study of rPAI materials requires a polymerization technique to achieve a soluble polymer without solid state ring closure of the amic acid bond. The work of Imai and coworkers8 and Buys and coworkers9 both indicated that the ring closure of amic acid to imide was done in the solid state at elevated temperatures. We have used their techniques to prepare dense films of rPAI materials and have found that the solid state thermal imidizations resulted in a high level of defective dense films.…”

“…A summary of the historical background of polyamide imides was presented in a recent doctoral thesis7 along with excellent synthetic details of model compound studies. The synthesis of rPAI materials have been reported in the literature 8, 9. In both of these literature citations the polymer was formed in solution by the reaction of trimellitic anhydride chloride (TMAc) with aromatic diamine(s) to form the amide amic acid.…”