Abstract: Linear perfluoropolyethers of formula: T-O(CF2O)n(CF2CF2O)m(CF2CF2CF2O)r(CF2CF2CF2CF2O)s-T1??(I) wherein n, m, r, s are integers such that the polymer number average molecular weight is comprised between 700 and 100,000 and the n/(n+m+r+s) ratio ranges from 0.05 to 0.40, and respective preparation process by addition of a peroxidic perfluoropolyether of formula (III): T4-O(CF2O)n?(CF2CF2O)m?(O)h-T5??(III) having a PO from 1.8 to 4, to a perfluoropolyether oil preheated at a temperature comprised between 150° C. and 250° C. and subsequent exhaustive fluorination of the obtained compound.

Abstract: A process for preparing peroxidic perfluoropolyethers having a peroxidic content (PO) higher than 1.2 of formula A-CF2O(CF2CF2O)m(CF2O)n—(CF2CF2OO)ml(CF2OO)nlCF2—B??(I) wherein A, B, equal to or different from each other are Cl—, F—, C1CF2—, COF—, —OCOF, —CF3, m, ml, n, nl are integers such that the (m+ml)/(n+nl) ratio is between 0.9 and 5 and the m/n ratio is between 0.8 and 3, the number average molecular weight is in the range 35,000-45,000, by tetrafluoroethylene (TFE) photooxidation in the presence of UV light, at a temperature from ?80° C. to ?40° C., in the presence of a mixture of solvents formed of HFC-227 (heptafluoropropane) and a solvent selected from HFC-125 (pentafluoroethane) and FC-218 (perfluoropropane).

Abstract: A process for preparing peroxidic perfluoropolyethers having a perioxidic content (PO) lower than or equal to 1.2 of formula A-CF2O(CF2CF2O)m(CF2O)n—(CF2CF2OO)m1(CF2OO)n1CF2—B??(I) Wherein A, B equal to or different from each other are —C1, —F, —F2CC1, —COF, —OCOF, —CF3, m, m1, n, n1 are integers such that the (m+m1)/(n+n1) ratio is between 0.6 and 1.3 and the m/n ration is between 0.5 and 1.2; the number average molecular weight is in the range 35,000-45,000, by tetrafluoroethylene (TFE) photooxidation in the presence of UV light, at a temperature from ?80° C. to ?40° C., in the presence of a mixture of solvents formed of HFC-227 (hepta-fluoropropane) and a solvent selected between HFC-125 (pentafluoroethane) and FC-218 (perfluoropropane).

Abstract: Peroxidic perfluoropolyethers having formula: X1—O(CF2O)n1(CF2CF2O)m1(CF2(CF2)zCF2O)p1(O)h—X2??(I) wherein: X1 and X2, equal to or different from each other, are chain end groups selected among —CF2COF, —COF, —SO2F; n1, m1, p1 and h are integers such that the number average molecular weight is in the range 700-100,000; z=1 or 2; with the proviso that: the m1/n1 ratio is between 0.2 and 10; the p1/(n1+m1) ratio is lower than 0.05; the h/(n1+m1+p1) ratio is such that the PO content, defined as grams of active oxygen/100 g of compound, is in the range 0.8-4.5, preferably 1.4-3.8; the perfluorooxyalkylene units being statistically distributed along the polymeric chain.

Abstract: Peroxidic perfluoropolyethers having formula: X1—O(CF2O)n1(CF2CF2O)m1(CF2(CF2)zCF2O)p1(O)h—X2 ??(I) wherein: X1 and X2, equal to or different from each other, are chain end groups selected between —CF2COF and —COF; n1, m1, p1 and h are integers such that the number average molecular weight is in the range 700-100,000; z=1 or 2; with the proviso that: the m1/n1 ratio is between 0.2 and 10; the p1/(n1+m1) ratio is lower than 0.05; the h/(n1+m1+p1) ratio is such that the PO content, defined as grams of active oxygen/100 g of compound, is in the range 0.8-4.5, preferably 1.4-3.8; the perfluorooxyalkylene units being statistically distributed along the polymeric chain.

Abstract: Use in optical systems as liquids to transmit light at wave lengths lower than 250 nm, in particular at 157 nm, of perfluoropolyethers having the following formula: X1—O(CF2O)n(CF2CF2O)m(CF2CF2CF2O)p (CF2CF2CF2CF2O)q—X2??(I) wherein: the repeating units —CF2O—, —CF2CF2O—, —CF2CF2CF2O—, —CF2CF2CF2CF2O— are statistically distributed along the chain; —X1 and —X2 are perfluoroalkyl chain end groups equal to or different from each other, having formula —(CF2)zCF3 wherein z is 0 or an integer from 1 to 3; n, m, p, q are 0 or integers comprised between 1 and 100, with the proviso that: at least one among n, m, p and q is different from zero; the ratio between the oxygen atoms and the carbon atoms (O/C) is higher than 0.33; wherein the chlorine atoms, determined by 19F-NMR are substantially absent.

Abstract: A process to obtain perfluoropolyethers comprising: a) synthesis of the peroxidic perfluoropolyether by one of the following reactions: a1) TFE photooxidation, in the presence of UV light, at low temperature, in solvents selected between perfluorocarbons and (mono)hydrofluorocarbons, of general formula: CyF(2y+2?x)Hx ??(II) wherein y is an integer from 2 to 4; x is an integer equal to 0 or 1; in the presence of fluorine diluted with an inert gas; or a2) TFE oxidation using as radical initiator fluorine or hypofluorites of formula RfOF (III) (Rf pefluoroalkyl radical from 1 to 3 carbon atoms), operating from ?40° C. to ?100° C. at a pressure comprised between 0 and 12 bar, in an inert solvent under the reaction conditions; b) thermal treatment of the product obtained in a) at a temperature from 150° C. to 250° C.

Abstract: Process for preparing peroxidic perfluoropolyethers by oxidation of tetrafluoroethylene with oxygen, in liquid phase comprising a solvent and in the presence of a chemical initiator, at a pressure between 2 and 15 absolute atm and operating with a molar ratio of the tetrafluoroethylene to the chemical initiator higher than 35. The process allows to increase the molecular weight of the perfluoropolyethers at the same content of peroxidic oxygen.

Abstract: Peroxy perfluoropolyoxyalkylenes are prepared with high yields by carrying out the photo-oxidation of tetrafluoroethylene with molecular oxygen, by means of ultraviolet radiations, operating in the presence of pentafluorochloroethane as a solvent for tetrafluoroethylene.Thus, it is possible to obtain peroxy perfluoropolyoxyalkylenes having a viscosity at 20.degree. C. ranging from 300,000 to 8,000,000 cSt and endowed with a peroxide content not higher than 4.Such perfluoropolyoxyalkylenes provide, through chemical reduction, perfluoropolyoxyalkylenes endowed with a functionality higher than 1.9 and at the same time with a high molecular weight.

Abstract: Process for the production of gamma- or delta-lactones according to the general formula: ##STR1## in which R is a saturated, mono-, di- or triunsaturated linear alkyl chain comprising from 2 to 10 carbon atoms and in which R.sub.1 is alkylene comprising 2 or 3 carbon atoms, entailing the operation which consists in culturing, in a substrate comprising a hydroxide or hydroperoxide of linoleic acid or of linolenic acid, of their esters or of their glycerides, or of an oleic acid derivative obtained by the photooxygenation of oleic acid or autoxidation of fats which contain it, a microorganism capable of performing beta-oxidations of said substrate.