Surface modification of fluoroelastomer by direct fluorination with fluorine gas

•The surface modification of fluoroelastomer by direct fluorination was investigated.•The surface of fluoroelastomer becomes smoother and cleaner after fluorination.•A greater number of CF3, CF2 and CF groups are formed after fluorination.•The surface of fluoroelastomer becomes more hydrophobic after fluorination.•Mechanical properties changed a little, while the friction coefficient is decreased.

The surface modification of fluoroelastomer by using direct fluorination with fluorine gas was investigated. The results of X-ray photoelectron spectroscopy (XPS) indicate that a greater number of CF3, CF2 and CF groups are formed on the surface after fluorination and the photographs of both scanning electronic microscopy (SEM) and three-dimensional digital microscope reveal that the surface of fluoroelastomer becomes smoother and cleaner after fluorination. In addition, the surface energy of fluoroelastomer is decreased and more hydrophobic surface is explored after fluorination due to the more fluorine-contained chemical structures. However, the mechanical properties of fluorinated fluoroelastomer have not been changed apparently, while the friction coefficient is sharply decreased.