Fluorine is the lightest halogen and existsas a highly toxic pale yellow diatomic gas at standard conditions. As the mostelectronegative element, it is extremely reactive: almost all other elements,including some noble gases, form compounds with fluorine.

H andF ions exchange on polymer surface form a very stable and compact C-F key.Materials performance of chemical-resistant, anti-aging and anti-penetration performance is greatly improved. At the same time, friction from the surfacewould be reduced.