Glycidyl Methacrylate-Grafted Poly(vinylidene fluoride- co -chlorotrifluoroethylene) as Solution-Processable and Ultraviolet-Cross-Linkable Fluoropolymer-Based Coating Material

Abstract

Fluoropolymer coatings are attractive for advanced surface-protection applications owing to their chemical resistance, thermal stability, low surface energy, and nonstick characteristics. However, their poor solution processability and weak interfacial compatibility often limit practical coating applications. Herein, we report a solution-processable and ultraviolet (UV)-post-cross-linkable fluoropolymer, poly(vinylidene fluoride-co-chlorotrifluoroethylene)-grafted-glycidyl methacrylate P(VDF-CTFE)-g-GMA, prepared by graft polymerization of GMA from a P(VDF-CTFE) backbone. By controlling the GMA feed ratio, graft copolymers with different epoxy functionalities were synthesized, and their structures were confirmed by Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. After blade coating of the polymer solution containing a photoacid generator, the films were cross-linked by UV irradiation through cationic ring-opening reactions of the epoxy groups. Solvent immersion tests and time-dependent Fourier-transform infrared spectroscopy (FT-IR) analysis confirmed the formation of an insoluble cross-linked network, while thermogravimetric analysis revealed changes in thermal decomposition behavior after UV curing. The cross-linked films also showed selective patternability through localized UV exposure and solvent development, increased gel content with UV exposure time, and water contact angles comparable to pristine P(VDF-CTFE). In addition, the cross-linked films demonstrated enhanced cross-cut adhesion on glass, aluminum, and silicon wafer substrates. These results indicate that P(VDF-CTFE)-g-GMA is a promising platform for solution-processable, UV-cross-linkable, and patternable fluoropolymer coatings.