Enhancing electrical strength of acrylate polymer by using fluorinated monomer as surface modifier

A novel method using ultraviolet (UV) cured fluoralkene to realize surface fluorination of acrylate polymer is proposed to enhance its insulation performance. Doping small amount of dofluoroheptyl methacrylate C ₁₁ H ₈ F ₁₂ O ₂ (DFHMA) in UV acrylate resin formulation as modifier can assemble a fluorinated monomolecular layer on the surface whenas bringing little change to its morphology. The influences of the modifier on molecular structure, surface free energy, elemental composition and electric properties of acrylate polymer are investigated by attenuated total reflection infrared (ATR-IR), water contact angle, X-ray photoelectron spectroscopy (XPS), and electrical performance characterizations, respectively. Experimental results indicate that DFHMA is segregated to the surface of acrylate polymer, leading to an increase of its surface hydrophobicity. Surface flashover tests reveal that fluorinated samples have a higher degradation or tracking resistance in comparison with virgin samples. In addition, strong C[sbnd]F bonds also can enhance bulk breakdown characteristics by increasing charge injection barrier.