SYNTHESIS AND CHARACTERIZATION OF 1,3-BIS(DICYANOMETHYLIDENE)INDANE (BDMI)-BASED NONLINEAR-OPTICAL POLYMERS

New polymers containing nonlinear optical chromophores of electron don or-bridge moieties amino-phenylenethienylidene (APT) coupled with a st rong electron acceptor 1,3-bis(dicyanomethylidene)indane (BDMI) were s ynthesised by coupling the aldehydic APT precursor polymers with accep tor BDMI in acetic anhydride. The aldehydic APT precursor polymers wer e prepared via traditional condensation or radical polymerisation sche mes where the aldehydic group of APT was found intact. Thermal stabili ty of these BDMI-based polymers determined by t.g.a. was up to 500 deg rees C depending mainly on the chromophore loading density. The electr o-optic coefficient (r(33)) of 10 pm V-1 was obtained in a 30% by weig ht chromophore loading polymer. (C) 1998 Elsevier Science Ltd. All rig hts reserved.