A novel approach to the synthesis of high 1,4-telechelic polybutadienes by an anionic route

Evidence is given that the presence of a sterically hindered Lewis acid during the anionic polymerization of butadiene in tetrahydrofuran results in a product with enhanced 1,4-content. Trimesityl boron was the Lewis acid principally employed and its influence allowed the 1,4-content to be raised to 50%. A relatively slow but competing proton abstraction reaction with the propagating polybutadienyl anion was, however, observed and alternative more specific additives are suggested.