Ks. Lee et al., AN ALTERNATIVE SYNTHETIC ROUTE TO SOLUBLE POLYETHERIMIDE DERIVATIVES WITH HIGH 2ND-ORDER OPTICAL NONLINEARITY, Advanced materials, 9(12), 1997, pp. 978
Processible polyetherimide-based polymers that display nonlinear optic
al (NLO) activity are reported to have been synthesized by the Mitsuno
bu reaction, in which the polyimide structure is synthesized directly
in a single step from a diimide and a diol, without a high-temperature
thermal imidization step. The resulting polymers, with pendant-incorp
orated tricyanovinyl azobenzene chromophores, showed very large second
-order NLO activity with good temporal and thermal stability-in one ca
se no decay of the signal was observed up to 125 degrees C.