5-Isobenzofurancarboxylic acid, 1,3-dihydro-1,3-dioxo-, polymer with 4,4'-oxybis(benzenamine) and 4,4'-(sulfonylbis(4,1-phenyleneoxy))bis(benzenamine) 72968-66-2 Benzenamine, 4,4'-(sulfonylbis(4,1-phenyleneoxy))bis-, polymer with4,4'-oxybisbenzenamine and 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid