Patent ID: 8349950

Claim:
An elastomeric polymer composition comprising miktopolymers of the structure (A 2 -B) n —X-(A 1 ), where a. A 1 and A 2 are each a polymer block of a monoalkenyl arene and B is a polymer block of one or more conjugated dienes or a hydrogenated polymer block of one or more conjugated dienes; b. n is an integer from 2 to 30; and c. X is the residue of a coupling agent; and wherein: i. τ is an asymmetry parameter of monoalkenyl arene associated with the A 1 and A 2 blocks according to the formula τ=NA 1 /(NA 1 +NA 2 ) where NA 1 is the number of monomer units in the A 1 monoalkenyl arene block and NA 2 is the number of monomer units in an A 2 monoalkenyl arene block; ii. f is the volume fraction of monoalkenyl arene in said miktopolymer; iii. τ has a value of 0.7 to 0.95; iv. f has a value greater than or equal to 0.4; and v. block A 1 has a peak molecular weight of between 10,000 and 300,000, where the ratio of the peak molecular weight of A 1 to A 2 is greater than or equal to 2.