Arylidene Polymers VII. Synthesis and Characterization of New Polyesters of Diarylidenecycloalkanones Containing an Azo Group in the Main Chain

Abstract

A new interesting class of linear, unsaturated polyesters based on diarylidenecycloalkanones containing an azo linkage in the polymer main chain have been synthesized by interfacial polycondensation of 4,4′-azodibenzoyl chloride or 3,3′-azodibenzoyl chloride with 2,5-bis(p-hydroxybenzylidene)cyclopentanone, 2,5-divanillylidenecyclopentanone, 2,6-bis(p-hydroxybenzylidene)cyclohexanone and 2,6-divanillylidenecyclohexanone at ambient temperature. The resulting polyesters were characterized by elemental analyses, IR spectroscopy, solubility and viscometry measurements. The thermal properties of the polymers were evaluated by TGA and DSC measurements and correlated to their structural units. X-ray analysis of the polymers showed that polyesters based on the meta azo linkage were totally amorphous whereas, polyesters with the para azo linkage had some degree of crystallinity. The UV-visible spectra of certain polymers were measured in m-cresol solution and showed a characteristic absorption band at 438-465 nm due to n-π* transition. In addition, the electrical properties of all polyesters were measured.