Low profile lubricants for data storage devices

1. A lubricant comprising: a plurality of segments according to general formula (I):

Re 1 —Rb 1 -Rc-Rb 2 —Re 2   (I);

wherein Rc is a divalent linking segment comprising general formula (II) or (IIa):

wherein R 2 comprises one or more of general formulas (ii) through (vi):

or a combination thereof;

wherein p, when present, is from 1 to 20;

wherein s, when present, is from 0 to 10;

wherein t, when present, is from 0 to 10;

wherein n, when present, is from 1 to 10;

wherein m, when present, is from 0 to 10;

wherein z, when present, is from 1 to 10;

wherein each R # , when present, is independently, H or F;

wherein each R 1 is an anchoring functional group engageable with a protective overcoat of a magnetic recording media;

wherein each of Rb 1 and Rb 2 independently comprises a chain segment comprising at least one of a fluoroalkyl ether moiety, a fluoroalkenyl ether moiety, a perfluoroalkyl ether moiety, a perfluoroalkenyl ether moiety, or a combination thereof; and

wherein each of Re 1 and Re 2 independently comprises two non-aromatic anchoring functional groups engageable with the protective overcoat of the magnetic recording media.

2. The lubricant of claim 1 , wherein each anchoring functional group comprises, at least one of B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR* 2 , —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR* 2 , —PO—(OR*) 2 , —O—PO—(OR*) 2 , —N═P(NR* 2 ) 3 , —AsR* 2 , —SR*, —SO 2 —(OR*) 2 , —BR* 2 , —SiR* 3 , —(CH 2 ) q —SiR* 3 , —(CF 2 ) q —SiR* 3 , or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C 1 -C 50 radical, an unsaturated C 2 -C 50 radical, an aromatic C 4 -C 50 radical, a polycyclic aromatic C 2 -C 50 radical, a heteroaromatic C 2 -C 50 radical, an alicyclic C 3 -C 50 radical, and/or a heterocyclic C 2 -C 50 radical, and wherein two or more R* may join together to form a ring structure.

3. The lubricant of claim 1 , wherein at least one anchoring functional group comprises a hydroxyl moiety (—OH).

4. The lubricant of claim 1 , wherein Rc comprises general formula (IIb):

wherein R 2 comprises one or more of formulas (ii) through (vi):

or a combination thereof;

wherein s, when present, is from 0 to 10;

wherein t, when present, is from 0 to 10;

wherein n is from 1 to 10;

wherein m, when present, is from 0 to 10;

wherein each R # , when present, is independently, H or F;

wherein each R 1 comprises at least one of B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR* 2 , —NR*—CO—R*,—O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR* 2 , —PO—(OR*) 2 , —O—PO—(OR*) 2 , —N=P(NR* 2 ) 3 , —AsR* 2 , —SR*, —SO 2 —(OR*) 2 , —BR* 2 , —SiR* 3 , —(CH 2 ) q —SiR* 3 , —(CF 2 ) q —SiR* 3 , or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C 1 -C 50 radical, an unsaturated C 2 -C 50 radical, an aromatic C 4 -C 50 radical, a polycyclic aromatic C 2 -C 50 radical, a heteroaromatic C 2 -C 50 radical, an alicyclic C 3 -C 50 radical, and/or a heterocyclic C 2 -C 50 radical, and wherein two or more R* may join together to form a ring structure.

5. The lubricant of claim 4 , wherein R 2 further comprises one or more of general formulas (ia) through (va):

—CF 2 CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) a CF 2 CF 2 CF 2 -;  (ia)

—CF 2 CF 2 O(CF 2 CF 2 CF 2 O) a CF 2 CF 2 -;  (iia)

—CF 2 CF 2 O[CF(CF 3 )CF 2 O] a CF 2 CF 2 -;  (iiia)

—CF 2 O(CF 2 CF 2 O) a (CF 2 O) b CF 2 -;  (iva)

—CF 2 O(CF 2 CF 2 O) a CF 2 -;  (va)

or a combination thereof;

wherein each a is, independently from 1 to 20, and

wherein each b, when present, is independently from 1 to 20.

6. The lubricant of claim 4 , wherein at least one anchoring functional group comprises a hydroxyl moiety (—OH).

7. The lubricant of claim 1 , wherein each of Rb l and Rb 2 independently comprises one or more of general formulas (ia) through (va):

—CF 2 CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) a CF 2 CF 2 CF 2 -;  (ia)

—CF 2 CF 2 O(CF 2 CF 2 CF 2 O) a CF 2 CF 2 -;  (iia)

—CF 2 CF 2 O[CF(CF 3 )CF 2 O] a CF 2 CF 2 -;  (iiia)

—CF 2 O(CF 2 CF 2 O) a (CF 2 O) b CF 2 -;  (iva)

—CF 2 O(CF 2 CF 2 O) a CF 2 -;  (va)

or a combination thereof,

wherein each a is, independently from 1 to 20, and

wherein each b, when present, is independently from 1 to 20.

8. The lubricant of claim 1 , wherein each of Re l and Re e independently comprises general formula (III):

wherein each R 1 is an anchoring functional group engageable with the protective overcoat of the magnetic recording media, and comprises at least one of: B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR* 2 , —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR* 2 , —PO—(OR*) 2 , —O—PO—(OR*) 2 , —N=P(NR* 2 ) 3 , —AsR* 2 , —SR*, —SO 2 —(OR*) 2 , —BR* 2 , —SiR* 3 , —(CH 2 ) q —SiR* 3 , —(CF 2 ) q —SiR* 3 , or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C 1 -C 50 radical, an unsaturated C 2 -C 50 radical, an aromatic C 4 -C 50 radical, a polycyclic aromatic C 2 -C 50 radical, a heteroaromatic C 2 -C 50 radical, an alicyclic C 3 -C 50 radical, and/or a heterocyclic C 2 -C 50 radical, and wherein two or more R* may join together to form a ring structure.

9. The lubricant of claim 8 , wherein at least one anchoring functional group comprises a hydroxyl moiety (—OH).

10. The lubricant of claim 1 , wherein the general formula (I)

Re 1 —Rb 1 -Rc-Rb 2 —Re 2   (I);

comprises general formula (V):

wherein a is from 1 to 20; and c is from 1 to 20.

11. The lubricant of claim 1 , wherein the general formula (I)

Re 1 —Rb 1 -Rc-Rb 2 —Re 2   (I);

comprises general formula (VI):

wherein a is from 1 to 20; and c is from 1 to 20.

12. The lubricant of claim 1 , comprising a weight average molecular weight from about 0.5 to 20 kiloDaltons (kDa), a polydispersity of greater than or equal to about 1 and less than or equal to about 2, or a combination thereof.

13. The lubricant of claim 1 , comprising a dewetting thickness of less than or equal to about 10 nanometers.

14. The lubricant of claim 1 , comprising a dewetting thickness of less than or equal to about 0.9 nanometers.

15. A magnetic recording medium, comprising:

a magnetic recording layer on a substrate;

a protective overcoat on the magnetic recording layer; and

a lubricant layer comprising the lubricant according to claim 1 on the protective overcoat.

16. The magnetic recording medium of claim 15 , wherein the lubricant has a bonding percentage of about 10% to less than 100%, corresponding to a degree of bonding of the lubricant to the total area of an upper surface of the protective overcoat.

17. The magnetic recording medium of claim 15 , wherein the lubricant comprises a dewetting thickness of less than or equal to about 10 nanometers.

18. A data storage system, comprising:

at least one magnetic head;

a magnetic recording medium comprising the lubricant of claim 1 ;

a drive mechanism for positioning the at least one magnetic head over the magnetic recording medium; and

a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

19. A data storage system, comprising:

a slider comprising at least one magnetic head and an air bearing surface (ABS), wherein a lubricant according to claim 1 is disposed on the ABS; and

a magnetic recording medium comprising a magnetic recording layer;

wherein the slider is configured to write information to the magnetic recording layer.