Fluorinated polymers are irradiated in order to initiate the degradation of the polymer chains and thus obtain low-molecular fluorinated polymers or oligomers.
Certain fluorinated polymers can also be crosslinked, some of them by using additives or under special irradiation conditions: PVDF (polyvinylidene fluoride) and ETFE (ethylene-tetrafluorethylene copolymer).
Irradiation of PVDF changes its ferroelectric properties. Radiation crosslinkable ETFE is used for cable insulation which has to withstand high temperatures. Self-limiting heating tapes for very high temperature ranges are insulated with radiation crosslinked ETFE.
PTFE is a material with high temperature stability and excellent chemical properties. PTFE degrades under irradiation. This degraded material is used as a lubricant and is added to other lubricants and to paints. Research in Japan and Germany has shown that PTFE can be radiation crosslinked by irradiating at very high temperatures, and can be used for applications requiring special ability to withstand very high temperatures.
For the manufacture of cable insulations and shrinkable products, radiation crosslinked compounds are used. With some compounds, gel values around 70% are achieved by irradiation with relatively small doses.