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Enhancement of gas selectivities of hexafluoroisopropylidene-based polyimides with poly(methylmethacrylate) blending / Hyungu Im in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8663–8669 Titre : Enhancement of gas selectivities of hexafluoroisopropylidene-based polyimides with poly(methylmethacrylate) blending Type de document : texte imprimé Auteurs : Hyungu Im, Auteur ; Hyomi Kim, Auteur ; Chang Keun Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 8663–8669 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Poor  gas  selectivity  Polyimides  Hexafluoroisopropylidene  diphthalic  anhydride  Hexafluoroisopropylidene  diamine  Diaminobenzoic  acid Résumé : To enhance poor gas selectivity of polyimides based on hexafluoroisopropylidene diphthalic anhydride (6FDA), such as 6FDA−4,4′-hexafluoroisopropylidene diamine (6FDA−6FpDA) and 6FDA−6FpDA:diaminobenzoic acid (6FDA−6FpDA:DABA), membranes were fabricated from their blends with poly(methylmethacrylate) (PMMA). The resulting polyimides formed homogeneous mixtures with PMMA, regardless of the blend compositions. The miscible blends underwent phase separation upon heating due to the lower critical solution temperature phase behavior. The phase separation temperature of the 6FDA−6FpDA/PMMA blend was greater than that of the 6FDA−6FpDA:DABA/PMMA when the composition was fixed. Adding a small amount of PMMA dramatically increased the gas selectivity of the membrane. In addition, the gas selectivity of most blends was better than that of pure PMMA. The membranes showed performance advantages for the trade-off trend between gas permeability coefficient and selectivity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900643p [article] Enhancement of gas selectivities of hexafluoroisopropylidene-based polyimides with poly(methylmethacrylate) blending [texte imprimé] / Hyungu Im, Auteur ; Hyomi Kim, Auteur ; Chang Keun Kim, Auteur . - 2010 . - pp. 8663–8669. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8663–8669 Mots-clés : Poor  gas  selectivity  Polyimides  Hexafluoroisopropylidene  diphthalic  anhydride  Hexafluoroisopropylidene  diamine  Diaminobenzoic  acid Résumé : To enhance poor gas selectivity of polyimides based on hexafluoroisopropylidene diphthalic anhydride (6FDA), such as 6FDA−4,4′-hexafluoroisopropylidene diamine (6FDA−6FpDA) and 6FDA−6FpDA:diaminobenzoic acid (6FDA−6FpDA:DABA), membranes were fabricated from their blends with poly(methylmethacrylate) (PMMA). The resulting polyimides formed homogeneous mixtures with PMMA, regardless of the blend compositions. The miscible blends underwent phase separation upon heating due to the lower critical solution temperature phase behavior. The phase separation temperature of the 6FDA−6FpDA/PMMA blend was greater than that of the 6FDA−6FpDA:DABA/PMMA when the composition was fixed. Adding a small amount of PMMA dramatically increased the gas selectivity of the membrane. In addition, the gas selectivity of most blends was better than that of pure PMMA. The membranes showed performance advantages for the trade-off trend between gas permeability coefficient and selectivity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900643p