However, scientists at the time generally believed that PTFE can only be pyrolyzed, and therefore doubted the result. The radiation crosslinking conditions of PTFE are harsh, and the radiation temperature range is very narrow. Using 60Co Y-ray or electron beam (EB) to irradiate PTFE can be Forms cross-linked PTFE. Due to the poor thermal conductivity of PTFE, there will also be a large local temperature difference between different parts of the sample, which makes it difficult to control the temperature of the sample. The chain cleavage PTFE Fiberglass Fabric free radicals can flow relatively freely and may approach each other and cause cross-linking reactions.
A few years later, Chinese and Japanese scientists have published papers on radiation crosslinking of PTFE. Professor Tabata from the University of Tokyo and others have conducted a serious discussion and believe that the research results of Sun Jiazhen and others are the same as those reported by Tujia Manming earlier.
However, Tujia Manming of Tokyo Metropolitan Institute of Isotope Research (now Tokyo Metropolitan Institute of Industrial Technology) first discovered in 1970 that the effect of high temperature irradiation of PTFE is very different from normal temperature irradiation, and it is speculated that crosslinking may have occurred phenomenon. Since 1992, Professor Tabata has cooperated with the Takasaki Institute of Radiation Chemistry (at that time), the Japanese Atomic Force Research Institute, to study the radiation crosslinking of PTFE. In order to obtain a better sample, a lot of effort is required to design and control the temperature of the high-temperature irradiation device.
In the middle and late 1980s, Sun Jiazhen of the Changchun Institute of Applied Chemistry of the Chinese Academy of Sciences and others proposed at an international conference that PTFE may have cross-linking, which attracted the attention of Japanese experts. Experiments have proved that under vacuum or inert atmosphere, it is slightly higher than the melting point of PTFE (Tm=327℃), that is, the temperature range is 330~340℃
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