R3 X3 ; orAlRX2,______________________________________ where R and R' represent hydrocarbon radicals, said R and R' being the same or different, wherein X is a halogen selected from the group consisting of bromine, chlorine, and iodine; wherein said non-conjugated diene is present in said A block up to about 2 mole percent, based on the total moles of the monomers of said block copolymer; wherein