Abstract: A poly(imide-ester-amide) copolymer and an optical film are provided. The poly(imide-ester-amide) copolymer includes imide bonds, ester bonds, and amide bonds. A molar ratio of the imide bonds, the ester bonds, and the amide bonds is 40 to 80:10 to 30:5 to 30. The imide bonds are derived from an aromatic diamine monomer and a tetracarboxylic dianhydride monomer. The amide bonds are derived from an aromatic dicarboxylic acid dichloride monomer and an aromatic diamine monomer or is derived from the aromatic dicarboxylic acid dichloride monomer and an alkoxysilane containing an amine group or an isocyanate group.

Abstract: A poly(imide-ester-amide) copolymer and an optical film are provided. The poly(imide-ester-amide) copolymer includes imide bonds, ester bonds, and amide bonds. A molar ratio of the imide bonds, the ester bonds, and the amide bonds is 40 to 80:10 to 30:5 to 30.

Abstract: A poly(amide-imide) copolymer, a composition for a thin film, and a thin film are provided. The poly(amide-imide) copolymer is synthesized by polymerization, dehydration cyclization, and hydrolysis condensation of an aromatic diamine monomer, a diacyl chloride monomer, a tetracarboxylic dianhydride monomer, and a silane compound having an alkoxy group as an end-capping agent. The aromatic diamine monomer includes 2,2?-bis(trifluoromethyl)benzidine. Based on a usage amount of 100 mol % of the aromatic diamine monomer, a usage amount of the 2,2?-bis(trifluoromethyl)benzidine is 70 mol % or more.

Abstract: This invention provides a polysulfone with a formula (I) as below: wherein, R2 independently represents a substituted or unsubstituted aromatic ring; X is a linking group having both an ester group and a hydroxyl group; R3 is an aliphatic linking group with more than 3 carbons or an aromatic linking group with at least two aromatic rings, and at least two of the aromatic rings are joined by an oxygen atom, a sulfur atom, a isopropylidene group or a hexafluoroisopropylidene group; and R? is an terminal group with an epoxy group.