| 摘要 |
Compounds usable as stabilizing additives of perfluoropolyether fluids working at high temperatures, higher than 200° C. and/or in the presence of metals and/or in the presence of Lewis acids, are formed of (per)fluoropolyether chains and of end groups having a heteroaromatic structure, according to the following general formula: <?in-line-formulae description="In-line Formulae" end="lead"?>T<SUB>1</SUB>-CFW<SUB>1</SUB>-O-R<SUB>f</SUB>-CFW<SUB>2</SUB>-T<SUB>2 </SUB> (I) <?in-line-formulae description="In-line Formulae" end="tail"?> wherein T<SUB>1</SUB>, T<SUB>2</SUB>, equal to or different from each other, have the following meanings: F, CF<SUB>3</SUB>, C<SUB>2</SUB>F<SUB>5</SUB>, (C<SUB>2</SUB>F<SUB>4</SUB>)Cl -CH<SUB>2</SUB>-B-Y, -CH(CF<SUB>3</SUB>)O-Y, wherein: B-O, S: Y is a substituent formed of a ring having a heterocyclic structure having the following formula: wherein: R<SUB>1</SUB>, R<SUB>2</SUB>, R<SUB>3</SUB>, R<SUB>4</SUB>, equal to or different from each other are H, linear or branched C<SUB>1</SUB>-C<SUB>8 </SUB>perfluoroalkyl, NO<SUB>2</SUB>, CN, preferably H; with the proviso that at least one of the two end groups T<SUB>1</SUB>, T<SUB>2 </SUB>is -CH<SUB>2</SUB>-B-Y or -CH(CF<SUB>3</SUB>)O-Y, wherein B and Y are as above: W<SUB>1</SUB>, W<SUB>2</SUB>, equal to or different from each other, are -F, -CF<SUB>3</SUB>: Rf is a (per)fluoropolyoxyalkylene chain having a number average molecular weight between 500 and 10,000, preferably between 800 and 5,000.
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