Cardo moieties

To see the effect of cardo moiety on gas separation properties, Banerjee et al. synthesized five phenyl-substituted phthalimidine side group-containing semifluorinated PAEs, entries 2GS-37 to 2GS-41) (Table 2.11) [102]. These PAEs were synthesized by aromatic nucleophilic substitution, starting from A-phenyl-3,3-fc/5(4-hydroxyphenyl)phthalimidine with five different perfluoroalkylated monomers l,3- 7/5(4 -fluoro-3 -trifluoromethyl benzyl) benzene. 

For PV application, fluorinated poly(arylene ether sulfone)s containing bulky cardo moiety and -CF3 groups have shown improvement in flux and separation factor owing to the increase in FFV and micro-phase-separated morphology allowing penetration of solvents into the membranes. However, fluorinated PAEs with various architectures need to be further explored for PV application. 

S. Ghosh,S.Banerjee,Fluorinatedpoly(arylene ether)s with aliphatic chain appended cardo moiety synthesis and gas transport properties, J. Memb. Sci. 470 (2014) 535-546. 

In a different smdy, they synthesized another five series of poly(ether imide)s based on five different cardo moiety containing diamines, designated as BPI, BAPA, FBP, BIDA, and SBPDA, as presented in Scheme 3.21. Five different aromatic dianhydride, 4,4 -(4,4 -isopropylidenediphenoxy) w(phthalic anhydride) (BPADA), 4,4 -(hexafluoro-isopropyli-dene) diphthalic anhydride (6-FDA), 3,3 4,4"-benzo-phenone tetracarboxylic acid dianhydride (BTDA), 4,4 -oxydiphthalic anhydride (ODPA), and benzene-1,2,4,5-tetracarboxylic dianhydride (PMDA), were used to prepare each series of poly(ether imide)s. The O2-N2 and CO2-CH4 separation properties for... 

The wholly aromatic processable PAs is achieved by modifying diamines, diacids, or both structures. The modification of the monomers can be broadly categorized in the four pathways to get the processable aromatic PA (i) incorporation of flexible spacers (ii) incorporation of bulky substructures as side substituent, (iii) incorporation of non-linear rigid alicyclic structures and cardo moieties and (iv) incorporation of fluorine as trifluoromethyl or a mixture of thereof. A short discussion on the monomers for the processable PAs has been described below. 

The cardo fluorene moiety was extensively studied to improve the solubility of PAs. Hu et al. [44] synthesized several PAs with fluore-nyl-cardo moieties in the main chain. Most of the pol)mtiers were readily soluble in polar aprotic solvents, and some were soluble in THE PAs exhibited better solubUity when alkyl substituents were incorporated. Wu and Shu [45] described the synthesis of soluble aromatic PAs derived from a diacid monomer with a spiro core, 2,2 -bis (4[Pg.131]

Table 5.2 Properties of the polyfether amide)s containing -CF substituent, ether linkage, bulky pendent groups and cardo moieties in the main chain (from [11,53-55]).

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