Surface modification of white PVC polymer by different plasma immersion techniques

Polymer substrates have several distinct advantages, such as, robustness, low density, impact resistance, and conformity over glass substrates for optical applications. Some applications are impeded, however, owing to its low adhesion to thin films, surface roughness, and low gas permeability. In this work, the wettability and the surface morphology of Poly(Vinyl) Chloride, PVC, samples were modified by plasma immersion. PVC was chosen because of its already wide use and low cost: PVC is used in floor coverings, plumbing, electrical insulation, hoses, containers, and other accessories. In this work, plasma immersion was used to modify the chemical structure of white PVC, producing high values of contact angles (θ > 100o) in fluorine plasmas, measured immediately after treatments, and until 30 days after. Also, it was detected low values of contact angles (θ < 50o) in nitrogen plasmas. Atomic Force Microscopy revealed smooth surfaces, whose roughness, Rz, was less than ~13 nm, except for plasma immersion cathode, which yielded a Rz of ~213 nm.