Fixation of bromine to carbon in products of electrochemical reduction of poly-(tetrafluoroethylene)

Abstract

Bromine reacts either in the gas phase or in an aqueous medium with carbon prepared by the electrochemical reduction of poly-(tetrafluoroethylene) with lithium amalgam. The primary reaction product, C(LiF) 2Li 0.21, is rather resistant against bromine at room temperature. The high reactivity of carbon in this mixture was manifested only after removal of the LiF matrix. Thus, the reaction with bromine was accomplished either by the action of water saturated with bromine, where LiF dissolved, or by heating the primary product at 300°C in a bromine atmosphere at 25 kPa (growth of LiF crystallites). The bromination products were studied by organic elemental analysis and XPS. The mechanism of the bromination is discussed in view of the content of C-H and C-Li groups and a high content of C atoms in an sp hybridization state.