(per)fluoropolyether polymers

1. A polymer (P), wherein polymer (P) is selected from the group consisting of:

polymers (P N ) comprising:

one (per)fluoropolyether chain (R pf ) and

at least one chain (C) comprising at least one hydroxy group and at least one amino group,

wherein chain (R pf ) is a chain of formula —(CFX) a O(R f )(CFX') b −, wherein

a and b, equal or different from each other, are equal to or higher than 1;

X and X′, equal or different from each other, are —F or —CF 3 , provided that when a and/or b are higher than 1, X and X′ are —F; and

(R f ) comprises repeating units R°, said repeating units being independently selected from the group consisting of:

 (i-a) —CF(CF 3 )O—;

 (ii-a) —CFXCFXO—, wherein X, equal or different at each occurrence, is F or CF 3 , with the proviso that at least one of X is —CF 3 ;

 (iii-a) —CF 2 CF 2 CF 2 O—;

 (iv-a) —CF 2 CF 2 CF 2 CF 2 O—;

 (v-a) —(CF 2 ) j —CFZ—O— wherein j is an integer from 0 to 3 and Z is a group of general formula —O—R( f-a )—T, wherein R (f-a) is a fluoropolyoxyalkene chain comprising a number of repeating units from 0 to 10, said recurring units being selected from: —CFXO—, —CF 2 CFXO—, —CF 2 CF 2 CF 2 O—, —CF 2 CF 2 CF 2 CF 2 O—, with each of each of X being independently F or CF 3 and T being a C 1 —C 3 perfluoroalkyl group; and

polymers (P N *) comprising

at least two (per)fluoropolyether chains (R pf ), each chain (R pf ) having two chain ends, wherein:

said at least two chains (R pf ) are linked together at one chain end through a divalent chain (*C*) comprising at least one hydroxy group and at least two amino groups, and

at least one of said at least two chains (R pf ) bears on its opposite chain end a monovalent chain (C*) comprising at least one hydroxy group and at least one amino group; and

wherein each chain (R pf ) is independently a chain of formula —(CFX) a O(R f )(CFX′) b —, wherein

a and b, equal or different from each other, are equal to or higher than 1;

X and X′, equal or different from each other, are —F or —CF 3 , provided that when a and/or b are higher than 1, X and X′ are —F;

(R f ) comprises repeating units R°, said repeating units being independently selected from the group consisting of:

 (i) —CFXO—, wherein X is F or CF 3 ;

 (ii) —CFXCFXO—, wherein X, equal or different at each occurrence, is F or CF 3 , with the proviso that at least one of X is —F;

 (iii) —CF 2 CF 2 CW 2 O—, wherein each of W, equal or different from each other, is F, Cl, or H;

 (iv) —CF 2 CF 2 CF 2 CF 2 O—; and

 (v) —(CF 2 ) j —CFZ—O— wherein j is an integer from 0 to 3 and Z is a group of general formula —O—R (f-a) —T, wherein R( f-a ) is a fluoropolyoxyalkene chain comprising a number of repeating units from 0 to 10, said recurring units being selected from: —CFXO—, —CF 2 CFXO—, —CF 2 CF 2 CF 2 O—, —CF 2 CF 2 CF 2 CF 2 O—, with each of each of X being independently F or CF 3 and T being a C 1 —C 3 perfluoroalkyl group.

2. The polymer (P) according to claim 1 , wherein in said polymer (P N *), said chains (R pf ) are bonded to the nitrogen atom of the amino groups of chain (*C*) and of chain (C*) via a group (B),

said group (B) being a divalent alkyl chain comprising from 1 to 20 carbon atoms, said alkyl chain being optionally interrupted by at least one oxygen atom and/or optionally substituted with at least one hydroxy group and/or with a perfluoroalkyl group comprising from 1 to 3 carbon atoms.

3. The polymer (P) according to claim 1 , wherein said polymer (P N *) comprises two chains (R pf ) and chain (*C*) comprises two amino groups.

4. The polymer (P) according to claim 1 , said polymer (P N *) complying with the following formula (P-I):

T-(R pf )—(B*)—(*C*)—(B*)—(R pf )—(B*)—(C*)  (P-I)

wherein

(R pf ) is a chain of formula —(CFX) a O(R f )(CFX′) b —;

wherein

a and b, equal or different from each other, are equal to or higher than 1;

X and X′, equal or different from each other, are —F or —CF 3 , provided that when a and/or b are higher than 1, X and X′ are —F;

(R f ) comprises repeating units R°, said repeating units being independently selected from the group consisting of:

(i) —CFXO—, wherein X is F or CF 3 ;

(ii) —CFXCFXO—, wherein X, equal or different at each occurrence, is F or CF 3 , with the proviso that at least one of X is —F;

(iii) —-CF 2 CF 2 CW 2 O—, wherein each of W, equal or different from each other, are F, Cl, H;

(iv) —CF 2 CF 2 CF 2 CF 2 O—; and

(v) —(CF 2 ) j —CFZ—O— wherein j is an integer from 0 to 3 and Z is a group of general formula —O —R( f-a )—T, wherein R( f-a ) is a fluoropolyoxyalkene chain comprising a number of repeating units from 0 to 10, said recurring units being selected from: —CFXO—, —CF 2 CFXO—, —CF 2 CF 2 CF 2 —, —CF 2 CF 2 CF 2 CF 2 O—, with each of each of X being independently F or CF 3 and T being a C 1 —C 3 perfluoroalkyl group

(B*) is a divalent alkyl chain comprising from 1 to 20 carbon atoms, said alkyl chain being optionally interrupted by at least one oxygen atom and/or optionally substituted with at least one hydroxy group and/or with a perfluoroalkyl group comprising from 1 to 3 carbon atoms;

(*C*) is a linear or branched alkyl chain comprising from 1 to 10 carbon atoms, and being optionally interrupted by at least one heteroatom selected from N, O and S and/or by a 5- to 10-membered aromatic moiety optionally comprising one or more heteroatoms and optionally substituted with a linear or branched alkyl chain comprising from 1 to 6 carbon atoms, said aromatic moiety and/or said alkyl chain being optionally substituted with at least one hydroxy group;

(C*) is a linear or branched alkyl chain comprising from 1 to 20 carbon atoms, said alkyl chain being optionally interrupted by one or more heteroatoms and being optionally substituted with a 5- to 10-membered aromatic moiety, or a 5- to 10-membered aromatic moiety optionally substituted with a linear or branched alkyl chain comprising from 1 to 6 carbon atoms, wherein said alkyl chain or said a 5- to 10-membered aromatic moiety further comprising at least one hydroxy group and at least one amino group; and

T is selected from the group comprising —H, —F, —Cl, a straight or branched perfluoroalkyl group comprising from 1 to 3 carbon atoms, and chain —(B*)—(C*).

5. A process for the manufacture of polymer (P N ) according to claim 1 , said process comprising:

reacting at least one PFPE alcohol with a compound bearing at least one sulfonic group to obtain a sulfonic PFPE ester, and

reacting the sulfonic PFPE ester with at least one organic amine to obtain polymer (P N ).

6. The process according to claim 5 , wherein the organic amine is an organic aliphatic or aromatic compound comprising at least one primary or secondary amine group.

7. A process for the manufacture of at least one polymer (P N *) according to claim 1 , said process comprising:

reacting at least one PFPE alcohol with a compound bearing at least one sulfonic group to obtain a sulfonic PFPE ester,

reacting the sulfonic PFPE ester with at least one polyamine to obtain a PFPE- oligomer comprising at least two chains (R pf ),

optionally purifying the PFPE-oligomer, and

reacting the PFPE-oligomer with at least one monoamine to obtain polymer (P N *).

8. The process of claim 7 , wherein reacting the sulfonic PFPE ester with at least one polyamine is performed in the presence of an excess of sulfonic PFPE ester.

9. A lubricant for magnetic recording media (MRM) comprising at least one polymer (P) according to claim 1 .