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The Influence of the Irradiation Temperature on the Ratio of Chain Scission to Branching Reactions in Electron Beam Irradiated Polytetrafluoroethylene (PTFE)
Author(s) -
Lappan Uwe,
Geißler Uwe,
Scheler Ulrich
Publication year - 2007
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.200600495
Subject(s) - branching (polymer chemistry) , polytetrafluoroethylene , irradiation , materials science , melting point , electron beam processing , cathode ray , polymer chemistry , analytical chemistry (journal) , composite material , electron , chemistry , organic chemistry , physics , quantum mechanics , nuclear physics
Polytetrafluoroethylene (PTFE) films have been irradiated by electron beam in vacuum at various temperatures ranging from room temperature up to temperatures far above the melting temperature. Changes of the chemical structure have been analyzed by 19 F solid‐state NMR and IR spectroscopy. The concentration of several structures generated by irradiation increases with increasing irradiation temperature up to the beginning of the thermal degradation. The molar ratio of >CF branching points to CF 3 end groups changes with crossing of the melting temperature. The generation of >CF branching points is accelerated if the PTFE is irradiated in the molten state, where branching reactions become more important.