Improvement on UHMWPE and PMMA Surface Flashover Under Atmospheric Pressure Using PIII Processing

Polymers are plastic materials used as insulators in power supplies, pulsers, transformers, etc., because of their low cost and excellent insulating properties. However, in several applications, the insulating performance of these materials is limited by the surface flashover instead of the dielectric bulk breakdown (BD). On the other hand, many works have demonstrated that the material hydrophobicity has a huge effect on the increase of resistance to surface flashover in polymers. In this article, to change this material property, the plasma immersion ion implantation (PIII) technique has been used for the treatment of sample surfaces of two important polymers: ultrahigh molecular weight polyethylene (UHMWPE) and poly-methyl-methacrylate (PMMA) used in medical and industrial applications, respectively. By means of the PIII treatment, it was shown that the surface BD voltage of such polymers has increased, improving the resistance to surface flashover. Contact angle diagnostic and atomic force microscopy (AFM) were measured, respectively, for the surface hydrophobicity and roughness to correlate with the increase of the surface BD voltage. Moreover, a special BD testing pulser is employed to assess the polymer resistance to surface flashover by measuring the corresponding BD voltage under atmospheric pressure.