Recent development of fluorine-containing transparent polymers

Polyfluorinated polymers have unique properties arise from the carbon-fluorine bonds which have small polarizability and strong bond energy. They exhibit the excellent chemical stability and the electrical characteristics (low-dielectric constant, low volume resistivity, low-dielectric loss and good electrical insulation property). The small polarizability carbon-fluorine bonds cause the low refractive index and high Abbe's number. The suppression of crystallization of the fluoropolymers, for example, by the introduction of cyclic ethereal structure in their main chains gives amorphous fluoropolymers such as Teflon AF and Cytop which are highly transparent from UV to near IR region. The recent advances on transparent fluoropolymers is marshaled in this paper. The 1,6-diene type monomer derived in only one step from octafluorocyclopentene was readily polymerized to form our new type of semifluorinated polymers containing the bicyclic ether structure (spiro and bicyclo structure).