Perfluoropolyether functional oligomers: unusual reactivity in organic chemistry

The chemistry of some functional perfluoropolyether (PFPE) macromolecules, synthesised by oxidative photopolymerisation of perfluoroolefins, is described. Starting from ethyl ester precursors different synthetic routes focused on α, ω-difunctional or monofunctional molecules are explored. These molecules are characterised by the following segmented structures:(I)RhCF2O(CF2CF2O)p(CF2O)qCF2Rh(II)Cl(C3F6O)nCF2RhSome significant examples showing the specific reactivity imparted by the fluorinated moiety to the molecule, together with important effects of phase separations on the selectivity, are presented. Reduction, hydrolysis, condensation and nucleophilic reactions are discussed. Within these categories, organic and inorganic ester formation and hydrolysis, ethers synthesis and amination reactions are analysed in depth. Analytical features (NMR and FT-IR) are presented and some mechanistic pathways proposed together with some kinetic studies. Finally, some significant examples of a new class of PFPE-containing polymers are reported and their morphology investigated by SEM and TEM analyses. The wide selection of the different constitutional components of structures (I) and (II) allows a fine tuning of their chemical and physical properties, giving rise to a new family of molecules with a broad range of application behaviour.