Several new polymeric materials containing push-pull azobenzene derivatives in the side chains were synthesized by polymer-analogous reactions involving the coupling of the diazonium salts of 4-substituted anilines with a preformed polymer, poly(N-methacryloyl-N'-phenylpiperazine). The second harmonic generation properties of these glassy macromolecular materials were investigated in order to understand the influence of the chromophore chemical structure on dipole orientability and stability of orientation. The results thus obtained were compared with those of analogous guest-host systems and a lack of chromophore mobility was highlighted for the side chain polymers. The use of a short flexible spacer should probably improve the NLO performance.