Characteristics of Colorless Fluorinated Imide-Based Oligomers for UV-Curing Coatings

UV-curable imide-based oligomers were synthesized using a thermal imidization approach to overcome the limitations of conventional polyimide coatings, such as their opaque, yellow appearance and their complex production methodologies. The developed UV-curable oligomers, specifically fluorinated imides with hydroxyl functionalities (FIOHs) and fluorinated imides with methacrylate functionalities (FIMAs), were thoroughly characterized using 1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel permeation chromatography, and rheological assessment via rheometry. The thermal, mechanical, and optical properties of the UV-cured films derived from FIMAs, in conjunction with two distinct cross-linkers, were evaluated using thermogravimetric analysis, a rigid-body pendulum tester, nanoindentation, nanoscratch testing, a universal testing machine, pencil hardness, an impact tester, ultraviolet–visible spectrophotometry, gloss meter, and colorimetry. The investigations revealed that the UV-cured imide-based oligomers demonstrated enhanced thermal stability, superior surface mechanical properties, and high optical transparency in the visible wavelength region. These attributes indicate that the UV-curable imide-based coatings are highly promising candidates for use in flexible display coating technologies.