Perfluoropolyether methyl propionate polysiloxane coating with high hydrophobicity and low dielectric property

Abstract Developing materials with a combination of superior properties such as hydrophobicity and low dielectric is very challenging. This work proposes a design strategy based on the synergistic effect of silicon fluorine to fabricate fluorous silicon materials with excellent hydrophobicity and dielectric properties. Perfluoropolyethyl propionate polysiloxane (PEPS) with different grafting ratios was synthesized by the reaction of polymethylhydrosiloxane (PMHS) and perfluoropolyethyl methacrylate (PPM) hydrosilane. The self‐crosslinking perfluoropolyether methyl propionate polysiloxane (PFSP) coating with good hydrophobicity and low dielectric was prepared by further introducing triethoxyvinylsilane (TOVS) into the PEPS and condensing. The fluorine content of two interfaces (film PET and film air) of PFSP‐4 film was analyzed by XPS, and it was found that the fluorine content of the film air interface was 46.19% and that of the film PET interface was 17.3%. With the increase of perfluoropolyether content in PFSP, fluorine‐containing groups migrate to the coating surface, which is more conducive to enhancing the hydrophobicity of the coating. The results indicate that the film has excellent hydrophobicity with a high water contact angle of up to 117° due to the introduction of PPM. In addition, the dipole moment of perfluoropolyether methyl methacrylate is 2.27, which is lower than that of methyl. Therefore, the introduction of a large number of perfluoropolyether bonds effectively reduces the polarity of the material, which is beneficial to its low dielectric properties. The dielectric constant of PFSP‐4 is 2.4, which is 33% lower than that of a fluorine‐free silicone coating. The results show that the self‐crosslinking perfluoropolyether methacrylate polysiloxane coating has excellent hydrophobicity and low dielectric properties, so it has a feasible application prospect in the electronic industry.