Superhydrophobic fluorinated polyester materials with low dielectric constant synthesized via facile preparation

Polyethylene terephthalate (PET) was widely utilized across diverse fields. However, its inferior hydrophobicity led to considerable practical losses and restricted its application scope. Herein, a new method was used to synthesize high-molecular-weight hydrophobic fluorinated polyester (FPET), effectively addressing the challenges of low reactivity and lengthy reaction times associated with fluorinated alcohols. By leveraging the excellent solubility of FPET, a superhydrophobic polyester material (PSPE) was prepared via solution blending of FPET with modified silica (F–SiO₂) and polytetrafluoroethylene (PTFE) particles. Accordingly, the water contact angle (WCA) of the resulting polyester increased from 67° (pristine PET) to 115°, confirming a significant improvement in hydrophobicity, which provided a foundation for achieving superhydrophobic modification. Furthermore, under PTFE particles and F–SiO₂, the hydrophobicity of the fluorinated polyester was further enhanced—achieving a maximum WCA of 159.5° and a minimum (SA) of 2.3°, which fully met the definition of superhydrophobicity. Even under a 100 g load, the sample maintained its superhydrophobicity after 50 abrasion cycles using sandpaper. Additionally, the incorporation of PTFE particles effectively reduced the dielectric constant of the polyester (dielectric constant ranged from 3.1 to 3.25), endowing it with favorable electrical insulation performance. This study presented an effective and viable strategy for synthesizing fluorinated polyesters with integrated superhydrophobicity, inherent self-cleaning ability, and low dielectric constant. Such multifunctional materials were expected to expand their application potential in water-repellent systems, anti-contamination coatings, and electronic packaging scenarios, addressing the key limitations of pristine PET.