Synthesis and nonlinear optical properties of high glass transition polyimides

Nonlinear optical (NLO) polymers with glass transition temperatures (T-g) a s high as 275 degrees C were prepared by covalent bonding of a chromophore to the backbone of hydroxyl polyimides via a Mitsunobu reaction. NLO side-c hain polyimides with different polymer backbones and different chromophores were prepared and characterized by second-harmonic generation. Poled films of the polymers have an excellent nonlinear optical response that is stabl e at elevated temperatures.