Synthesis and Characterization of Poly(aryl ether chalcone)s for Second Harmonic Generation

Abstract

The synthesis of a new class of poly(aryl ether chalcone)s is described by a polycondensation reaction of 4,4‘-difluorochalcone with various bisphenols in the excess anhydrous potassium carbonate in sulfolane/toluene mixture solvent. Fluoride atoms located at the para position of the chalcone moiety were found to be very activated toward nucleophilic aromatic substitution, and high molecular weight polymers were obtained. These polymers are amorphous and with glass transition temperatures at 150−200 °C and are very soluble in solvent such as chloroform and N -methylpyrrolidinone (NMP). The onset decomposition temperatures by thermogravimetric analysis of these materials were all above 330 °C. High optical quality films were obtained by spin-coating the polymer solution of NMP. The cutoff wavelength was shorter than 410 nm. The refractive indexes of these polymers at different wavelengths are reported. The corona poled polymers have different symmetry structures from the reported polymers, both P- and S-polarized SHG have been observed in these polymers.