2D infrared correlation study of the effect of base catalyst on thermal imidization of polyamic acid

The thermally induced structural changes of 6FDA-ODA PAA films in the presence and absence of a base catalyst, 2,6-dimethyl piperidine, were investigated using in situ FTIR spectroscopy. In addition, principal component analysis (PCA) and 2D correlation spectroscopy (2D-COS) were applied to clarify the thermal imidization behaviors. Based on the PCA results, we can confirm the various products formed during thermal imidization. The results of 2D correlation analysis revealed the thermally induced changes in the spectra of the 6FDA-ODA PAA films. In addition, we propose that the thermal imidization of the 6FDA-ODA PAA film in the presence of a base catalyst, 2,6-diemthyl piperidine, starts at a lower temperature than it does in the absence of a base catalyst. [Display omitted] •Thermal imidization behaviors of 6FDA-ODA PAA films with base catalyst.•Principal component analysis of polyamic acid in the presence of base catalyst.•2D correlation analysis of temperature dependent FTIR spectra during thermal imidization.