Patent EA-001231-B1 (EA)
Title: Method of metalation and functionalization of polymers and copolymers
Inventor: FRECHET JEAN M J
IPC: C08F8/00
Filed: 1996-06-06
Abstract: 1. A method of introducing functionality into a copolymer of an isoolefin and an alkylstyrene at the alkylbenzyl carbon atom comprising the steps of: forming a solution of the copolymer in a hydrocarbon solvent; adding to the polymer solution an alkali metal alkoxide, other than an alkoxide of lithium, and an alkyl lithium compound to form a superbase in the polymer solution and adding an electrophile to the polymer solution, wherein the superbase is present in an amount relative to the alkylstyrene content of the copolymer to provide a mole ratio of from about 1:1 to about 2:1, and a mole ratio between the alkali metal alkoxide and an alkyl lithium is from about 1:1 to about 5:1. 2. The method of claim 1, wherein the mole ratio between the alkali metal alkoxide and an alkyl lithium is from about 1:1 to about 3:1. 3. The method of claim 1, wherein the alkali metal alkoxide and alkyl lithium are added sequentially. 4. The method of claim 1, wherein the alkali metal alkoxide and alkyl lithium are first reacted to provide superbase and the superbase is added to the polymer solution. 5. The method of claim 1, wherein the alkali metal alkoxide is an alkoxide of sodium, potassium, or cesium. 6. The method of claim 5, wherein the alkali metal alkoxide is an alkoxide of cesium. 7. The method of claim 5, wherein the alkyl lithium compound is a secondary alkyl lithium compound. 8. The method of claim 7, wherein the alkyl lithium compound is sec-butyl lithium. 9. The method of claim 1, wherein the alkylstyrene is p-alkylstyrene. 10. The method of claim 1, wherein the p-alkylstyrene is p-methylstyrene. 11. The method of claim 1, wherein the copolymer is an isobutylene-paramethystyrene copolymer. 12. The method of claim 1,wherein the electrophile is selected from the group consisting of acylchlorides, CO2, CS2, aliphatic chlorides, benzylic chlorides, allylic chlorides, fluoroaromatics substituted with an electron withdrawing group, silylchloride, aldehydes, ketones, carbonates, esters and anhydrides. 13. A copolymer comprising: the product resulting from reaction of a reaction product of a copolymer of a monoisoolefin and an alkylstyrene with a superbase and an electrophilic reagent which is formed resulting from reaction of an alkali metal alkoxide, other than the alkoxide of lithium, and an alkyl lithium compound. 14. The copolymer of claim 13 represented by the formula:   wherein "a" is in the range of 1 to 70,000, "b" in the range of 1 to 7,000, and "c" in the range of 0 to 7.000, wherein a >= b + c, R1 and R2 are each independently a C1-C5 alkyl and R1 + R2 <= 5 carbon atoms; R3 and R4 are each independently one of hydrogen, a C1-C4 alkyl group fragment and E is an electrophile. 15. The copolymer of claim 14 wherein the electrophile is selected from the group of aldehydes, ketones, esters, organic halides, acylhalides,trialkyisilyl halides, sulfonyl halides benzyl halides, aliplatic halides, silylic halides, enones, fluoroaroaramatyl, epoxides, episulfides, CO2, and polymeric fragments containing electrophillic groups. 16. The copolymer of claim 15 wherein the fragment is CO2, ethylene oxide or episulfides. 17. The composition of claim 13 said composition being optically active. 18. A random copolymer represented by the formula:   wherein "a" is in the range of 1 to 70,000, "b" in the range of 1 to 7,000 and "c" in the range of 0 to 7,000, wherein a >= b + c, R1 and R2 are each independently a C1-C5 alkyl and R1 + R2 <= 5 carbon atoms; R3 and R4 are each independently one of hydrogen, a C1-C4 alkyl group fragment and M is an alkali metal other than lithium. 19. The copolymer of claim 18 wherein M is Na, K, Cs. 20. The copolymer of claim 19, wherein the alkylstyrene and the functionalized alkylstyrene are p-alkyl and p-functionalized alkylstyrene. 21. A method of metalating a copolymer of an isoolefin and an alkylstyrene at the primary benzylic carbon atom, said process comprising the steps of: forming a solution of said copolymer in a hydrocarbon solvent; adding to said polymer solution an alkali metal alkoxide, other than alkoxide of lithium, and an alkyl lithium compound and recovering the metalated copolymer. 22. The method of claim 21 wherein the alkali metal alkoxide and alkyl lithium are added sequentially.