WO1996036650B1 - Metalation and functionalization of polymers and copolymers - Google Patents

Abstract

There is provided 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 said copolymer in a hydrocarbon solvent; adding to said polymer solution an alkali metal Cs, K, Na alkoxide and an alkyl lithium compound to form a superbase with the polymer solution; and adding an electrophile to said base polymer solution also provided are the metalated copolymers and the functionalized derivative therefrom.

Claims

AMENDED CLAIMS

[received by the International Bureau on 10 January 1997 (10.01.97);

original claim 14 amended; remaining claims unchanged (1 page)]

11. The method of Claim 1, wherein the copolymer is an isobutylene-paramethylstyrene copolymer.

12. The method of Claim 1, wherein the electrophile is selected from the group consisting of acyl chlorides, CO₂, CS₂, aliphatic chlorides, benzylic chlorides, allylic chlorides, fluoroaromatics substituted with an electron withdrawing group, silylchloride, aldehydes, ketones, carbonates, esters and anhydrides. 13. A composition comprising:

the product resulting from reaction of a reaction product of a copolymer of a moncisoolefin and a alkylstyrene with a superbase and an electrophilic reagent. 14. The composition 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, R₁ and R₂ are each independently a C₁ to C₅ alkyl or hydrogen, provided that at least one of R₁ and R₂ is alkyl and R₁ + R₂≤ 5 carbon atoms; R₃ - R₄ are each independently one of hydrogen, a C₁ to C₄ alkyl group fragment and E is an electrophile. 15. The composition of Claim 14 wherein the fragment is from one of aldehydes, ketones, esters, organic halides, acyl halides, trialkylsilyl halides, sulfonyl halides benzyl halides, aliplatic halides, silylic halides, enones, fluoroaroaramatyl, epoxides, episulfides CO₂, and polymeric fragments containing electrophillic groups. STATEMENT UNDER ARTICLE 19(1)

Functionalization of isoolefin-alklylstyrene copolymers via metalation with alkali metal Cs, K, Na alkoxide and alkyl lithium superbase formation is previously unknown. Metalation of other styrenic polymers with alkyl lithium activated with TMEDA in prior art, and with alkyl lithium/K alkoxide superbase, results in product wherein main chain and/or aromatic ring carbon atoms are metalated and functionalized, and/or incomplete metalation/functionalization of p-alkyl group of the styrene unit. In accordance with this invention, little or no main chain/aromatic ring metalation occurs and essentially complete metalation of the p-alkyl group of the styrene unit can be obtained.