Synthesis and characterization of poly(tetrafluoroethyleneperoxides)

Hydrophobic carbonaceous materials obtained by covalent bonding of perfluorocarbon and perfluoropolyether chains

“…19 These latter are thermodynamically unstable and instantaneously rearrange to acyl fluorides by eliminating HF (Scheme 3b). Carbonyl fluoride and primary perfluorinated alcohols were formed (Scheme 3a) as side-products.…”

“…19 These latter are thermodynamically unstable and instantaneously rearrange to acyl fluorides by eliminating HF (Scheme 3b). 19 Therefore during the thermal decomposition, some PFPE radicals maintain undecomposed peroxidic moieties inside the chain. 22 A comparison between average molecular weight (MW A ) and equivalent molecular weight (MW E ) of PFPE peroxide 4 shows that the average number of peroxidic units present in the Scheme 4 PFPE radicals linked to the carbon black (CB) can react with neighbour sites on the surface (bridging) or with free PFPE radicals (coupling).…”

“…Carbonyl fluoride and primary perfluorinated alcohols were formed (Scheme 3a) as side-products. 19 These latter are thermodynamically unstable and instantaneously rearrange to acyl fluorides by eliminating HF (Scheme 3b). 26 Marchionni et al reported that the thermal-induced homolysis of peroxidic bonds in linear PFPE peroxides, similar to peroxide 4, generates reactive radical species with PFPE structure.…”

“…15 Perfluorodiacyl (PFDA) peroxides are also typical perfluoroalkylating agents 16 and in 1983 Zhao et al proposed a single electron-transfer mechanism for the perfluoroalkylation reaction with electron rich aromatic substrates. 19 In the present work, chemical treatments with fluorinated peroxides were used for the covalent linkage of several fluorinated residues to two different carbonaceous matrices: a graphitic carbon black (CB) and a DLC film. 18 Similar to PFDA peroxides, perfluoropolyether (PFPE) peroxides thermally decompose through the homolytic cleavage of the peroxidic units present along their polymeric backbone, generating reactive carbon-centred PFPE radicals obtained by rapid b-scission of the initially formed PFPE alkoxy radicals.…”

“…18 Similar to PFDA peroxides, perfluoropolyether (PFPE) peroxides thermally decompose through the homolytic cleavage of the peroxidic units present along their polymeric backbone, generating reactive carbon-centred PFPE radicals obtained by rapid b-scission of the initially formed PFPE alkoxy radicals. 19 In the present work, chemical treatments with fluorinated peroxides were used for the covalent linkage of several fluorinated residues to two different carbonaceous matrices: a graphitic carbon black (CB) and a DLC film. Perfluorodipropionyl (PFDP) 1, perfluorodi-n-butyryl (PFDnB) 2 and perfluorodi-isobutyryl (PFDiB) 3 peroxides were used for the perfluoroalkylation reaction.…”