Novel partially bio-based fluorinated polyimides from dimer fatty diamine for UV-cured coating

A series of novel partially bio-based fluorinated polyimides with double-bond end groups (BGPIs) from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride, 4,4′-(hexafluoroisopropylidene) dianiline, Priamine 1074, 4-aminobenzoic acid, and glycidyl methacrylate were synthesized via a copolycondensation method in m -cresol. The chemical structure and performances of BGPIs were fully characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, solubility test, X-ray diffraction, and differential scanning calorimetry. It was determined that the prepared BGPIs were in the amorphous phase and readily soluble in conventional aprotic polar solvents. Additionally, the properties of as-prepared UV-cured coatings based on BGPIs were also evaluated by real-time Fourier transform infrared, thermogravimetric analysis, UV–Vis spectroscopy, and so on. Results revealed that all coatings exhibited satisfactory curing, higher adhesion, lower water uptakes, outstanding optical transparency, and fairly favorable thermal stability under a high content of biomass up to 48.9%. Therefore, these bio-based polymers could be considered as a potential sustainable candidate for high-temperature UV-curable coatings in the microelectronic field.