1H,3H-Benzo[1,2-c:4,5-c']difuran-1,3,5,7-tetrone, polymer with 1,2-benzenediamine, 1,3-benzenediamine, 1,4-benzenediamine, 4-[4-[1-[4-[(1,3-dihydro-1,3-dioxo-5-isobenzofuranyl)oxy]phenyl]-1-methylethyl]phenoxy]-1,3-isobenzofurandione, 1,3-isobenzofurandione, 4,4'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bis[1,3-isobenzofurandione] and 5,5'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bis[1,3-isobenzofurandione]