The present invention includes compositions suitable for tire treads or sidewalls and other articles where abrasion resistance and flexibility are desirable. The invention includes a tire tread or sidewall made by combining a filler; a sulfur cure system; optionally at least one secondary rubber; and at least one halogenated terpolymer of C.sub.4 to C.sub.8 isoolefin derived units, C.sub.4 to C.sub.14 multiolefin derived units, and p-alkylstyrene derived units. Examples of suitable fillers include carbon black, silica, and combinations thereof. The present invention also includes a method of producing an elastomeric terpolymer composition comprising combining in a diluent C.sub.4 to C.sub.8 isoolefin monomers, C.sub.4 to C.sub.14 multiolefin monomers, and p-alkylstyrene monomers in the presence of a Lewis acid and at least one initiator to produce the terpolymer. Examples of suitable initiators include cumyl compounds and or halogenated organic compounds, especially secondary or tertiary halogenated compounds such as, for example, t-butylchloride, 2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy 2-phenyl propane (cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethyl ether)); the cumyl halides, particularly the chlorides, such as, for example 2-chloro-2-phenylpropane, cumyl chloride (1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene (di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene (tri(cumylchloride)); the aliphatic halides, particularly the chlorides, such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl), and 2-bromo-2,4,4-trimethylpentane (TMPBr).
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage Application of International Application No. PCT/US02/39433, filed Dec. 9, 2002, which claims the benefit of Provisional Application No. 60/339,966, filed Dec. 10, 2001.
The present invention includes blends of a halogenated elastomer such as a butyl rubber or an interpolymer of, on one embodiment, a C.sub.4 to C.sub.7 isomonoolefin, a para-methylstyrene and a para-(halomethylstyrene), the interpolymer having been pre-mixed with an exfoliating compound and clay, the entire blend forming a nanocomposite in one embodiment. The clay may or may not have undergone an additional exfoliating treatment prior to blending with the halogenated elastomer. The interpolymer/clay mixture forms a distinct phase in the nanocomposite blend of the invention. The blend of the invention has improved air barrier properties and is suitable as an air barrier.
