Characteristics of\nColorless Fluorinated Imide-Based\nOligomers for UV-Curing Coatings

UV-curable imide-based oligomers were synthesized using\na thermal\nimidization approach to overcome the limitations of conventional polyimide\ncoatings, such as their opaque, yellow appearance and their complex\nproduction methodologies. The developed UV-curable oligomers, specifically\nfluorinated imides with hydroxyl functionalities (FIOHs) and fluorinated\nimides with methacrylate functionalities (FIMAs), were thoroughly\ncharacterized using <sup>1</sup>H nuclear magnetic resonance, Fourier\ntransform infrared spectroscopy, gel permeation chromatography, and\nrheological assessment via rheometry. The thermal, mechanical, and\noptical properties of the UV-cured films derived from FIMAs, in conjunction\nwith two distinct cross-linkers, were evaluated using thermogravimetric\nanalysis, a rigid-body pendulum tester, nanoindentation, nanoscratch\ntesting, a universal testing machine, pencil hardness, an impact tester,\nultraviolet–visible spectrophotometry, gloss meter, and colorimetry.\nThe investigations revealed that the UV-cured imide-based oligomers\ndemonstrated enhanced thermal stability, superior surface mechanical\nproperties, and high optical transparency in the visible wavelength\nregion. These attributes indicate that the UV-curable imide-based\ncoatings are highly promising candidates for use in flexible display\ncoating technologies.