determined by gpc to have a number average molecular weight mn of 193 000 and a weight average molecular weight mw of 198 000 the mwd mw mn of this polymer was 1 03 this example clearly validated the formation of dilithio species in the example i since the molecular weight of the polymer was double of the target value in this example a telechlic functionalized polybutadiene containing 4 4 u2032 bis diethylamino benzophenol functional groups on both polymer chain ends was prepared the procedure described in example 2 was utilized in these examples except that two molar quantity to di li of 4 4 u2032 bis diethylamino benzophenone was added to the live cement after the polymerization of 1 3 butadiene was completed the tg and microstructures of this functionalized pbd were identical to polymer made in example 2 the mooney viscosity ml 4 at 100 u00b0 c for this polymer was 48 in this example a telechlic functionalized styrene butadiene rubber sbr containing tributyl tin groups on both polymer chain ends was prepared the procedure described in example 2 was utilized in these examples except that a premix containing styrene 1 3 butadiene in hexanes was used as the monomers and the styrene to 1 3 butadiene ratio was 15 85 in addition 0 75 molar ratio of tmeda n n n u2032 n u2032 tetramethylethylenediamine to di lithium was used as the modifier two molar quantities to di.