Compared properties of polyimides containing pendant azobenzene groups

Two series of aromatic polyimides containing pendant azobenzene groups have been investigated. One series contains isopropylidene bridge and the other series contains hexafluoroisopropylidene bridge in the dianhydride segment. These azo-polyimides have been studied by using thermal analysis, molecular modeling and spectral methods (UV, FTIR). The photochromic behavior, determined by the trans-cis isomerization process of azo-groups, in solution and in solid state, was also evaluated.