Azo Chromophore-Functionalized Polyelectrolytes. 1. Synthesis, Characterization, and Photoprocessing

A series of azobenzene chromophore-functionalized polyelectrolytes have been synthesized by a post-azo-coupling reaction. An epoxy-based precursor polymer (CH-AN) was synthesized by the reaction of 1,4-cyclohexanedimethanol diglycidyl ether (CH) with aniline (AN). For comparison purposes, another epoxy-based precursor polymer (BP-AN) was prepared from the diglycidyl ether of bisphenol A (BP) and aniline (AN). These precursor polymers were then postfunctionalized by an azo-coupling reaction to form polymers containing donor−acceptor type azo chromophores. The azo chromophores were designed to contain ionizable groups to impart self-assembling and photoprocessing capabilities to the polymers. The structure and properties of the newly synthesized polymers are reported in this paper. CH-AN-based azo polymers exhibit typical properties of polyelectrolytes. The polymers containing 4-(4-(carboxylic acid)phenylazo)aniline chromophores can be directly photofabricated to form surface relief gratings with large surface modulations. Charge interactions had a strong influence on the details of the writing process.