Diaminobiphenyl-2,2 -disulfonic acid BDSA

If 5,5 -dimethylbenzidine-2,2 -disulfonic acid (DMBDSA) [59], 2,5-di-aminobenzenesulfonic acid (DABSA) [60], and 4,4 -diaminostilbene-2,2 -di-sulfonic acid (DSDSA) [64] are scarcely used, 4,4 -diaminobiphenyl-2,2 -disulfonic acid (BDSA) has been the most employed in recent years. 

BDSA. See d -Diaminobiphenyl-l -disulfonic acid (BDSA) 3,3,4,4,Bcnzophcnonctctracaiboxylic dianhydride (BTDA), 297 Benzoxazine intermediates, 392 Benzoxazines, 391, 416-417... 

Suda et al. [288] reported the synthesis and characterization of a series of sulfonated star-hb polyimides (S-hb-Pls) without any crosslinking for use as proton exchange membranes. Sulfonated anhydride-terminated polyimides with different molecular weights (M v = 59,000, 200,000 and 300,000 Da) based on monomer combination 1,4,5,8-naphthalene tetracarboxylic dianhydride/4,4 -diaminobiphenyl 2,2 -disulfonic acid (NTDA/BDSA) were synthesized using different molar ratios of BDSA NTDA. The amine-terminated hb-Pl based on monomer combination 4,4-(hexafluoroisopropylidene)diphthalic anhydride/tris(4-aminophenyl)amine (6EDA/TAPA) was also prepared. Scheme 33 shows the monomer combinations used for the preparation of (S-hb-Pl). 

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