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.