Stability control of the electrooptic effect with new maleimide copolymers containing photoreactive tricyanopyrrolidene-based chromophores

New photocrosslinkable maleimide copolymers have been synthesized by the attachment of a tricyanopyrrolidene-based chromophore. The 2-(3-cyano-4-(2-{4- [hexyl-(6-hydroxy-hexyl)-amino]-phenyl}-vinyl)-5-oxo-l-{4-[4-(3-oxo-3-phenyl- propenyl)-phenoxy]-butyl)-1,5-dihydro-pyrrol-2-ylidene)-malononitrile chromophore exhibits non-linear optical activity and contains a chalcone moiety that is sensitive to UV light (λ = 330-360 nm) for crosslink formation. The maleimide monomers have also been functionalized with chalcone moieties. The resultant copolymers exhibit great processability, and one of them shows a maximum electrooptic coefficient of 90 pm/V at 1300 nm. We could control the thermal stability of the electrooptic coefficient with the newly synthesized photoreactive copolymers successfully.