Poly(amide-imide) copolymer, method of manufacturing the same, poly(amide-imide) copolymer film, window for display device, and display device

A poly(amide-imide) copolymer, comprising:

• an amide structural unit comprising an amide bond included in a polymer main chain, and imide structural units comprising an imide bond included in the polymer main chain,
• wherein the imide structural units comprise:
• a first imide structural unit comprising a moiety cross-linked to an adjacent polymer main chain through an amide bond, and
• a second imide structural unit, which is not cross-linked to an adjacent polymer main chain,
• wherein the first imide structural unit comprises a structural unit represented by Chemical Formula 1
• wherein, in Chemical Formula 1,
• X is the same or different in each structural unit and is independently a substituted or unsubstituted C6 to C20 monocyclic aromatic group, a substituted or unsubstituted C4 to C20 monocyclic non-aromatic group, a substituted or unsubstituted C8 to C20 condensed polycyclic aromatic group, a substituted or unsubstituted C6 to C20 condensed polycyclic non-aromatic group, a substituted or unsubstituted C6 to C20 non-condensed polycyclic aromatic group, a substituted or unsubstituted C6 to C20 non-condensed polycyclic non-aromatic group, or a combination thereof, wherein each of the substituted or unsubstituted C6 to C20 non-condensed polycyclic aromatic group and the substituted or unsubstituted C6 to C20 non-condensed polycyclic non-aromatic group are linked by a single bond or a linking group comprising a substituted or unsubstituted fluorenyl group, O, S, C(═O), OC(═O), S(═O), S(═O)2, C(═O)NH, CRa(OH), SiRbRc, or (CRdRe)p (1≤p≤10), wherein Ra to Re are independently hydrogen, a C1 to C30 alkyl group, a C1 to C30 haloalkyl group, a halogen, or a hydroxy group,
• Y is the same or different in each structural unit and is independently a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C3 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C3 to C20 heteroarylene group, or a combination thereof, and
• R11 is the same or different in each structural unit and is independently a single bond or a divalent organic group comprising a substituted or unsubstituted C6 to C30 aromatic or non-aromatic ring, wherein the aromatic or non-aromatic ring is present as a single ring;
• two or more aromatic or non-aromatic rings are condensed to provide a condensed polycyclic aromatic group;
• or two or more aromatic or non-aromatic rings are linked by a single bond or a linking group comprising a substituted or unsubstituted fluorenyl group, O, S, C(═O), OC(═O), S(═O), S(═O)2, C(═O)NH, CRf(OH), SiRgRh, or (CRiRj)p (1≤p≤10) to provide a non-condensed polycyclic aromatic group, wherein Rf to Rj are independently hydrogen, a C1 to C30 alkyl group, a C1 to C30 haloalkyl group, a halogen, or a hydroxy group, and
• * is a linking point of the polymer main chain.