AbstractThe absorption spectra of a series of polyamic acids prepared using various reaction conditions were studied using the ultraviolet (UV), visible, and near‐infrared (IR) ranges. The near‐IR proved most valuable; the amidization and imidization processes could be followed by observing the change of intensities of the 1950‐nm combination amine band and a band at 2300 nm assumed to be a function of the amide
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