STUDIES ON RADIATION EFFECTS OF PTFE .1. CHANGES IN CRYSTALLIZING BEHAVIOR AND NUMBER AVERAGE MOLECULAR-WEIGHT OF PTFE IRRADIATED AT DIFFERENT TEMPERATURES

The present work deals with changes in the number average molecular weight (MBAR(n)) of PTFE irradiated at different temperatures. A decrease in MBAR(n) was observed and attributed to the scission of polymer chains. On the other hand, it was also observed that MBAR(n) decreased to a minimum value with increasing irradiation dose and then increased; the doses at which the minimum value of MBAR(n) occurs are temperature dependent. The increase is explained as being due to cross-linking reactions occurring during the irradiation of PTFE.