Synthesis and properties of novel polyurethanes containing 3,4-dioxybenzylidenecyanoacetate group as a nonlinear optical chromophore

Abstract

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-toluenediisocyanate, 3,3′-dimethoxy-4,4′-biphenylenediisocyanate, and 1,6-hexamethylenediisocyanate to yield polyurethanes 4–6 containing the nonlinear optical chromophore 3,4-dioxybenzylidenecyanoacetate. The resulting polyurethanes 4–6 were soluble in common organic solvents such as acetone and dimethylformamide. Polymers 4–6 indicated thermal stability up to 300 °C in thermogravimetric thermograms with glass-transition temperature values obtained from differential scanning calorimetric thermograms in the range of 78–102 °C. The second-harmonic generation coefficients (d33) of the poled polymer films were around 6.9 × 10−9 esu. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1742–1748, 2002