The use of FTIR spectroscopy for determination of the optimalregime of enamelling process with polyesterimide enamels

摘要

This paper deals with the kinetics of curing and thermaldegradation processes of commercially availableTHEIC-polyesterimide-based enamels. All investigations were performed onthe enamel samples from enamelling wires manufactured with realequipment. Fourier transform infrared (FTIR) spectroscopy was employedto monitor the polymer cure and thermal degradation during wireenamelling. It has been found that process of polymer cure isaccompanied by the reducing of hydroxyl group concentration andconsequently by the reducing of the OH groups absorption intensity.Detailed study of the hydroxyl IR absorption region identified separatebands sensitive to the polymer structurization and destruction. It hasbeen found that the increase of the OH intensity of carboxylic groups at3228 cm-1 can be utilised to monitor the thermal degradation.It was shown that analysis of the hydroxyl groups region in the wireenamel IR-spectra allows determination of the optimal enamelling regimefor the equipment. IR-spectrum of enamel film from enamelled wire hassome additional information about physical structure of the polymerwhich may be used for prediction of some macroscopic wire properties.For example, area of the absorption band at 3630 cm-1 isresponsible for the value of prestretch in the flexibility test