Functionalized polymer, rubber composition and pneumatic tire

1. A functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I

where X is Cl, Br, or I;

m is an integer from 0 to 1, n is an integer from 2 to 3, with the proviso that n+m=3;

R 1 , R 2 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R 1 , R 2 are independently —SiR 3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 1 and R 2 taken together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom to form a five to eight membered ring;

R 3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R 3 is —SiR 3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 3 is -R 6 -R 7 , where R 6 is C1 to C3 alkanediyl and R 7 is selected from the following structures

—S—Z, —N(R 8 )(R 9 ), —O(Y), or Si(OR 10 ) 3 , where R 8 and R 9 are independently C1 to C18 alkyl, aryl, or a combination thereof,

Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyl dimethyl silyl, tert-butyl diphenyl silyl, and isopropyldimethylsilyl, and

R 10 are independently C1 to C4 alkyl;

or when m=1, the polymerization terminator may have the formula II

where R 4 , R 5 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R 4 , R 5 are independently —SiR 3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, X and R 3 are as defined previously, and k is an integer from 0 to 10.

2. The functionalized elastomer of claim 1 , wherein the living anionic elastomer is derived from at least one diene monomer and optionally at least one vinyl aromatic monomer.

3. The functionalized elastomer of claim 1 , wherein the living anionic elastomer is derived from at least one of isoprene and butadiene, and optionally from styrene.

4. The functionalized elastomer of claim 1 , wherein the living anionic elastomer is derived from butadiene and styrene.

5. The functionalized elastomer of claim 1 , wherein the polymerization terminator is selected from one of the following structures

6. A rubber composition comprising the functionalized elastomer of claim 1 .

7. The rubber composition of claim 6 , further comprising silica.

8. A pneumatic tire comprising the rubber composition of claim 7 .

9. A functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I

where X is Cl, Br, or I;

m is 0, 1 or n is 1 or 3, with the proviso that n+m=3;

R 1 , R 2 are methyl groups;

R 3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R 3 is —SiR 3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 3 is -R 6 -R 7 , where R 6 is C1 to C3 alkanediyl and R 7 is selected from the following structures

—S—Z, —N(R 8 )(R 9 ), —O(Y), or Si(OR 10 ) 3 , where R 8 and R 9 are independently C1 to C18 alkyl, aryl, or a combination thereof,

Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyl dimethyl silyl, tert-butyl diphenyl silyl, and isopropyldimethylsilyl, and

R 10 are independently C1 to C4 alkyl;

or when m=1, the polymerization terminator may have the formula II

where R 4 , R 5 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R 4 , R 5 are independently —SiR 3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, X and R 3 are as defined previously, and k is an integer from 0 to 10.

10. The functionalized elastomer of claim 9 , wherein the living anionic elastomer is derived from at least one diene monomer and optionally at least one vinyl aromatic monomer.

11. The functionalized elastomer of claim 9 , wherein the living anionic elastomer is derived from at least one of isoprene and butadiene, and optionally from styrene.

12. The functionalized elastomer of claim 9 , wherein the living anionic elastomer is derived from butadiene and styrene.

13. A rubber composition comprising the functionalized elastomer of claim 9 .

14. The rubber composition of claim 13 , further comprising silica.

15. A pneumatic tire comprising the rubber composition of claim 14 .