FTIR analysis of polyester enamel cure

This paper deals with the cure mechanisms of commercially available polyester-based enamels for magnet wire insulation coating applications. Fourier transform infrared (FTIR) spectroscopy was employed to monitor the cure. It has been found that the reduction of the OH intensity can be utilized to monitor the cure. The slight increase and shift of carbonyl bands were also observed, indicating both crosslinking bondings and complexation could be formed. The enamel cure process involves: (1) solvent evaporation; (2) rapid molecular weight buildup/crosslinking during solvent evaporation; and (3) cure saturation. The degree of cure was also evaluated.