Terminal-functionalized polymer, rubber composition containing same and related processes

1. A terminal-functionalized polymer having a structure according to formula I

(P) n Si(R) k (OR) m —SP—U  (I)

wherein P is a polymer chain comprising at least one type of conjugated diene monomer and optionally at least one type of vinyl aromatic monomer,

n is an integer of 1-3, m is an integer of 0-2, k is an integer of 0 or 1, m+n+k=3,

each R is independently selected from: (i) an alkyl group having 1 to 20 carbons, (ii) a cycloalkyl group having 3 to 20 carbons, (iii) an aryl group having 6 to 20 carbons, (iv) an alkylaryl group having 7 to 20 carbons, or (v) SiR 1 R 2 R 3 where each of R 1 , R 2

and R 3 is independently selected from H, (i), (ii), (iii), or (iv)

SP is a spacer group having at least two carbon atoms and is optionally substituted with at least one heteroatom selected from S, O, or NR, and

U is a moiety containing at least two carbon-carbon double bonds in a conjugated configuration.

2. The terminal-functionalized polymer of claim 1 , wherein U comprises a conjugated bond-containing cyclic moiety.

3. The terminal-functionalized polymer of claim 1 , wherein U comprises a moiety selected from

a. conjugated aromatics having at least one vinyl substituent,

b. conjugated non-aromatic cyclics, and

c. conjugated aliphatics.

4. The terminal-functionalized polymer of claim 3 , wherein U comprises (a) having 8-22 carbon atoms.

5. The terminal-functionalized polymer of claim 3 , wherein U comprises (b) having 5-20 carbon atoms.

6. The terminal-functionalized polymer of claim 4 , wherein U comprises vinylbenzene.

7. The terminal-functionalized polymer of claim 5 , wherein U comprises cyclopentadiene.

8. The terminal-functionalized polymer of claim 1 , wherein the at least one type of conjugated diene monomer is present and comprises 1,3-butadiene.

9. A process for preparing a terminal-functionalized polymer, the process comprising reacting the live end of a polymer chain with a functionalizing compound having formula II, wherein the polymer chain comprises at least one type of conjugated diene monomer and optionally at least one type of vinyl aromatic monomer,

(OR) o Si(R) p —SP—U  (II)

wherein o is an integer of 2-3, p is an integer of 0-1, o+p=3,

each R is independently selected from: (i) an alkyl group having 1 to 20 carbons, (ii) a cycloalkyl group having 3 to 20 carbons, (iii) an aryl group having 6 to 20 carbons, (iv) an alkylaryl group having 7 to 20 carbons, or (v) SiR 1 R 2 R 3 where each of R 1 , R 2 and R 3 is independently selected from H, (i), (ii), (iii), or (iv),

SP is a spacer group having at least two carbon atoms and is optionally substituted with at least one heteroatom selected from S, O, or NR, and

U is a moiety containing at least two carbon-carbon double bonds in a conjugated configuration.

10. The process of claim 9 , wherein U comprises a conjugated bond-containing cyclic moiety.

11. The process of claim 9 , wherein U comprises a moiety selected from:

a. conjugated aromatics having at least one vinyl substituent,

b. conjugated non-aromatic cyclics, and

c. conjugated aliphatics.

12. The process of claim 11 , wherein U comprises (a) having 8-22 carbon atoms.

13. The process of claim 11 , wherein U comprises (b) having 5-20 carbon atoms.

14. The process of claim 12 , wherein U comprises vinylbenzene.

15. The process of claim 13 , wherein U comprises cyclopentadiene.

16. The process of claim 9 , wherein the at least one type of conjugated diene monomer is present and comprises 1,3-butadiene.

17. A terminal-functionalized polymer prepared according to the process of claim 9 .

18. The terminal-functionalized polymer of claim 3 , wherein U is a moiety selected from (a).

19. The terminal-functionalized polymer of claim 3 , wherein U is a moiety selected from (b).

20. The terminal-functionalized polymer of claim 3 , wherein U is a moiety selected from (c).