Polyfunctional (per)fluoropolyethers

1. A (per)fluoropolyether comprising at least one (per)fluoropolyoxyalkylene chain (chain R f ) comprising at least one recurring unit (R2) having formula: —CF 2 CF(CF 2 OSO 2 F)—O— (poly(fluorosulfate) PFPE).

2. The poly(fluorosulfate) PFPE of claim 1 , wherein the chain R f comprises recurring units (R1), said recurring units having general formula: —(CF 2 ) k —CFZ—O—, wherein k is an integer of from 0 to 3, and wherein Z is selected between a fluorine atom and a C 1 -C 5 perfluoro(oxy)alkyl group.

3. The poly(fluorosulfate) PFPE of claim 1 complying with formula (I) here below:

X—O(CF 2 O) s (CF 2 CF 2 O) m (CFYO) n (CF 2 CFYO) p (CF 2 CF(CF 2 OSO 2 F)O) q —(CF 2 (CF 2 ) z CF 2 O) r —(WO) x —(O) t —X′ (I), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X and X′, equal to or different from each other, are functional groups independently selected from the group consisting of —COF, —CF 2 COF, —CF(CF 3 )COF and —SO 2 F and C 1 -C 3 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

Y is a C 1 -C 5 perfluoro(oxy)alkyl group;

W represents a C 2 -C 50 chain comprising recurring units, equal to or different from each other, of formula —(CR 1 R 2 —CR 3 R 4 )—, wherein R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are independently selected from the group consisting of hydrogen, halogen atoms, C 1 -C 6 (per)haloalkyl groups and C 1 -C 6 (per)fluoro(oxy)alkyl groups;

z is 1 or 2;

m, n, p, r, s, t and x are integers ≧0, and q is an integer ≧1.

4. The poly(fluorosulfate) PFPE of claim 1 complying with formula (II-A) here below: XO(CF 2 O) s (CF 2 CF 2 O) m (CF 2 CF(CF 2 OSO 2 F)O) q —(CF 2 (CF 2 ) z CF 2 O) r —(O) t —(WO) x —X′ (II-A), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X and X′, equal to or different from each other, are functional groups independently selected from the group consisting of —COF, —CF 2 COF, —SO 2 F and C 1 -C 2 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

W represents a C 2 -C 50 chain comprising recurring units, equal to or different from each other, of formula —(CR 1 R 2 —CR 3 R 4 )—, wherein R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are independently selected among halogen atoms and C 1 -C 6 (per)haloalkyl groups;

z is 1 or 2;

m, q, r and s are integers >0, x is an integer ≧0, q is an integer >1, and t is an integer ≧1.

5. The poly(fluorosulfate) PFPE of claim 1 complying with formula (II-B) here below: X—O(CF 2 O) s (CF 2 CF 2 O) m (CF 2 CF(CF 2 OSO 2 F)O) q —(CF 2 (CF 2 ) z CF 2 O) r —(WO) x —X′ (II-B), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X and X′, equal to or different from each other, are functional groups independently selected from the group consisting of —COF, —CF 2 COF, —SO 2 F, and C 1 -C 2 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

W represents a C 2 -C 50 chain comprising recurring units, equal to or different from each other, of formula —(CR 1 R 2 —CR 3 R 4 )—, wherein R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are independently selected from the group consisting of halogen atoms and C 1 -C 6 (per)haloalkyl groups;

z is 1 or 2;

m, q, r and s are integers >0, x is an integer ≧0, and q is an integer >1.

6. A process for manufacturing the poly(fluorosulfate) PFPE of claim 1 comprising the step of reacting a (per)fluoropolyether peroxide (peroxidic PFPE) with CF 2 ═CFCF 2 OSO 2 F (FAFS).

7. The process of claim 6 , wherein the peroxidic PFPE complies with formula (IV) here below: C—O—(CFX 1 O) c1 (CFX 2 CFX 3 O) c2 (CF 2 CF 2 CF 2 O) c3 (CF 2 CF 2 CF 2 CF 2 O) c4 (O) p —C′ (IV), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X 1 , X 2 , X 3 , equal to or different from each other, are independently selected from the group consisting of a fluorine atom and C 1 -C 5 perfluoro(oxy)alkyl groups;

C and C′, equal to or different from each other, are functional groups independently selected from the group consisting of COF, —CF 2 COF, —CF(CF 3 )COF, and C 1 -C 3 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

c1, c2, c3, and c4, equal to or different from each other, are integers ≧0, chosen so that (c1+c2+c3+c4) is in the range between 5 and 2000; and

p is an integer >0.

8. A process for manufacturing the poly(fluorosulfate) PFPE of claim 1 comprising the step of oxidatively photopolymerizing at least one ethylenically unsaturated perfluoromonomer with CF 2 ═CFCF 2 OSO 2 F (FAFS).

9. The process of claim 8 , wherein the ethylenically unsaturated perfluoromonomer is tetrafluoroethylene (TFE) and/or hexafluoropropylene (HFP).

10. A method for manufacturing a functional (per)fluoropolyether derivative comprising the step of utilizing the poly(fluorosulfate) PFPE of claim 1 .

11. The method according to claim 10 , wherein the functional (per)fluoropolyether derivative complies with formula (V) here below:

XO(CF 2 O) s (CF 2 CF 2 O) m (CF 2 CF(T)O) q —(CF 2 (CF 2 ) z CF 2 O) r —(O) t —(WO) x —X′ (V), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X and X′, equal to or different from each other, are functional groups independently selected from the group consisting of -T and —CF 2 T and C 1 -C 2 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

W represents a C 2 -C 50 chain comprising recurring units, equal to or different from each other, of formula —(CR 1 R 2 —CR 3 R 4 )—, wherein R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are independently selected from the group consisting of halogen atoms and C 1 -C 6 (per)haloalkyl groups;

T is a functional group selected from the group consisting of carboxylic acid groups, acyl fluoride groups, amide groups, and ester groups;

z is 1 or 2;

m, q, r and s are integers >0, t and x are integers ≧0, and q is an integer >1.

12. A method for manufacturing a functional (per)fluoropolyether derivative comprising the step of reacting the poly(fluorosulfate) PFPE of claim 1 with a nucleophilic agent.

13. The method according to claim 12 , wherein the nucleophilic agent is selected from the group consisting metal halogenides, alcoholates, and amines.

14. The method according to claim 12 , wherein the functional (per)fluoropolyether derivative complies with formula (V) here below: XO(CF 2 O) s (CF 2 CF 2 O) m (CF 2 CF(T)O) q —(CF 2 (CF 2 ) z CF 2 O) r —(O) t —(WO) x —X′ (V), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X and X′, equal to or different from each other, are functional groups independently selected from the group consisting of -T and —CF 2 T and C 1 -C 2 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

W represents a C 2 -C 50 chain comprising recurring units, equal to or different from each other, of formula —(CR 1 R 2 —CR 3 R 4 )—, wherein R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are independently selected from the group consisting of halogen atoms and C 1 -C 6 (per)haloalkyl groups;

T is a functional group selected from the group consisting of carboxylic acid groups, acyl fluoride groups, amide groups, and ester groups;

z is 1 or 2;

m, q, r and s are integers >0, t and x are integers ≧0, and q is an integer >1.

15. A method for manufacturing a functional (per)fluoropolyether derivative comprising the step of utilizing the poly(fluorosulfate) PFPE of claim 1 , wherein said utilizing the poly(fluorosulfate) PFPE comprises the step of reacting the poly(fluorosulfate) PFPE with a nucleophilic agent.

16. The method according to claim 15 , wherein the functional (per)fluoropolyether derivative complies with formula (V) here below: XO(CF 2 O) s (CF 2 CF 2 O) m (CF 2 CF(T)O) q -(CF 2 (CF 2 ) z CF 2 O) r —(O) t —(WO) x —X′ (V), the recurring units being statistically distributed along the (per)fluoropolyoxyalkylene chain, wherein:

X and X′, equal to or different from each other, are functional groups independently selected from the group consisting of -T and —CF 2 T and C 1 -C 2 (per)fluoroalkyl groups optionally containing one or more hydrogen or chlorine atoms;

W represents a C 2 -C 50 chain comprising recurring units, equal to or different from each other, of formula —(CR 1 R 2 —CR 3 R 4 )—, wherein R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are independently selected from the group consisting of halogen atoms and C 1 -C 6 (per)haloalkyl groups;

T is a functional group selected from the group consisting of carboxylic acid groups, acyl fluoride groups, amide groups, and ester groups;

z is 1 or 2;

m, q, r and s are integers >0, t and x are integers ≧0, and q is an integer >1.