RADIATION INDUCED CROSSLINKING OF POLYTETRAFLUOROETHYLENE

摘要

The irradiation effect of polytetrafluoroethylene (PTFE) was examined by tensile test and thermal analysis in a wide range of irradiation temperature. The tensile strength and elongation at break changed very much by irradiation temperature, especially around the PTFE melting temperature (327℃). By electron beam irradiation under vacuum in the molten state at around 340℃, the dose required for the half decay of the elongation at break was about 1 MGy, and the modulus and yield strength increased with dose, whereas the dose for the half decay at room temperature irradiation was less than 50 kGy, and the modulus and yield strength decreased. The crystallinity decreased by the irradiation in the molten state, but increased with dose below the melting temperature. It is concluded that network is formed with the crosslinking of PTFE by irradiation under vacuum in the molten state just above the melting point.