Copolymer containing new thermally reversible click chemistry-assisted triazole-substituted azobenzene and fulgimide units in the pendant F-Co-A was prepared by free-radical solution addition polymerization technique. The F and A were also prepared for comparison. The DSC analysis of F indicates that the polymer possessing the C-form of fulgimide unit exhibited higher T-m than that of E-form of the same polymer and revealed that the C-form of fulgimide unit in F is highly ordered. The cis-trans back isomerization behavior of the click chemistry-assisted triazole-substituted azobenzene unit in film A has thermal irreversibility, while in F-co-A it exbibited thermal reversibility. The UV-exposed film of F-co-A heated around T-g leads to cis-trans back isomerization of azobenzene unit and thermally stable C-form of fulgimide which retains its conjugated structure where both the photochromic units are converted into planar conformations and exhibit high fluorescence properties. The fluorescence maxima of C-form in F-co-A red shifted compared with F, because the substituted triazole ring in the azobenzene unit stabilized the C-form of fulgimide unit. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7843-7860, 2008