Infra-red Spectra of Terephthalic Polyester Enamelled Films

Abstract

The polycondensation and thermal degradation of polyester which happen simultaneously during the baking of enamelled wire were studied by infra-red spectra. The curing proceeds by mutual esterification and estsr interchange, and carboxylic groups are produced by thermal degradation of polyesters. It is found that the optical density of OH stretching band is more convenient for analysis than that of OH deformation band. In OH stretching frequency region there are four absorption bands and two of which have been assigned, but the rest are yet unknown. The optical densities of these unknown bands decrease with the progress of curing.
Furthermore the properties of polyester enamelled wire as crazing, colour, solvent-resistance and abrasion-resistance are found to have an intimate connection with the optical density of infra-red spectra of the baked film.