Fluorination of elastomer materials

The present study aims at the surface functionalization of cross-linked natural rubber films by direct fluorination routes involving the treatment of elastomer surfaces with gaseous fluorine and its mixtures. Two different fluorination methods were evaluated to attach fluorine moieties on polyisoprene surfaces. On the one hand the fluorination was carried out with mixtures of fluorine with inert gas yielding highly non-polar surfaces. On the other hand polar surface properties were obtained in the presence of fluorine and oxygen in the reaction gas mixture (oxy-fluorination). The functionalized surfaces were characterized by means of FTIR-ATR spectroscopy and contact angle measurements. Optical microscopy was used to assess the surface morphology of the modified elastomer films and the depth of fluorination was investigated with SEM-EDX. In addition, the influence of the surface fluorination on the mechanical properties, aging stability and stability against high energy radiation (e.g. gamma-rays) of the functionalized rubber materials were determined by tensile tests.