5-Isobenzofurancarboxylic acid, 1,3-dihydro-1,3-dioxo-, polymer with 4,4'-oxybis(benzenamine) and 3,3'-(sulfonylbis(4,1-phenyleneoxy))bis(benzenamine) 72968-67-3 Benzenamine, 3,3'-(sulfonylbis(4,1-phenyleneoxy))bis-, polymer with4,4'-oxybisbenzenamine and 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid