Synthesis of novel polyurethanes containing dioxybenzylidenecyanoacetate, as non-linear optical chromophores and their properties

Methyl 3,4-di-(2'-hydroxyethoxy)benzylidenecyanoacetate (3) was prepared by hydrolysis of methyl 3,4-di- (2'-vinyloxyethoxy)benzylidenecyanoacetate (2). Diol 3 was condensed with 2,4-toluene-diisocyanate, 3,3'-dimethoxy-4,4'-biphenylenediisocyanate, and 1,6-hexamethylenediisocyanate to yield polyurethanes 4, 5 and 6 containing the non-linear optical (NLO) chromophore 3,4-dioxybenzylidenecyanoacetate. The resulting polyurethanes 4-6 were soluble in common organic solvents such as acetone and DMF. T-g values of the polymers obtained from DSC thermograms were in the range 80-102degreesC. Polymers 4-6 showed thermal stability up to 300 C in TGA thermograms, and electro-optic coefficients (r(33)) of the poled polymer films were in the range 10-12 pm V-1 at 63 3 nm, which are acceptable for NLO device applications. (C) 2002 Society of Chemical Industry.