Linear perfluoropolyether difunctional oligomers: chemistry, properties and applications

The synthesis of telechelic perfluoropolyether oligomers (PFPE) is described. The preparation of these fluorinated derivatives of the structure R-h-CF2(OCF2)(q)(OCF2CF2)(p)OCF2-R-h was performed by condensation or nucleophilic reactions starting from PFPE precursors bearing carboxylic or alcoholic functional groups. A large variety of selective synthetic routes have been explored, differences in comparison with conventional hydrogenated molecules emphasized, and the related mechanisms elucidated. High yields and selectivities were generally observed, this enables to isolate oligomers of high purity, whose properties can be easily fine-tuned by varying the structural parameters. Some interesting chemical and physical properties are shown; and potential, highly innovative applications briefly discussed. (C) 1999 Elsevier Science S.A. All rights reserved.